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<h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Wendepunkt</span></h1>
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<p>In der <a href="Mathematik" title="Mathematik">Mathematik</a> ist ein <b>Wendepunkt</b> ein Punkt auf einer <a href="Kurve_(Mathematik)" title="Kurve (Mathematik)">Kurve</a>, an dem diese ihr <a href="Kr%C3%BCmmung" title="Krümmung">Krümmungsverhalten</a> ändert. Sie wechselt hier entweder von einer Rechts- in eine Linkskurve oder umgekehrt. Ein wichtiger Spezialfall sind Wendepunkte von <a href="Funktionsgraph" title="Funktionsgraph">Funktionsgraphen</a>, die im Folgenden betrachtet werden.
Die Ermittlung der Wendepunkte eines Funktionsgraphen ist Bestandteil einer <a href="Kurvendiskussion" title="Kurvendiskussion">Kurvendiskussion</a>.
</p><p>Die erste Abbildung zeigt ein Beispiel dazu: Hier ist der Funktionsgraph (blau) links vom Punkt W rechtsgekrümmt („Rechtskurve“) und rechts vom Punkt W linksgekrümmt („Linkskurve“). Demnach ist W ein Wendepunkt.
</p><p>Die <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/87f9e315fd7e2ba406057a97300593c4802b53e4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle x}" loading="lazy"></span>-Koordinate eines Wendepunkts nennt man häufig <b>Wendestelle</b> (z.&nbsp;B. mit <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span> bezeichnet). <a href="Tangente" title="Tangente">Tangenten</a> durch einen Wendepunkt (im Bild rot gezeichnet) heißen <b>Wendetangenten</b>. Wendepunkte, in denen diese Wendetangenten horizontal verlaufen, werden <a href="Sattelpunkt" title="Sattelpunkt">Sattel-, Terrassen- oder Horizontalwendepunkte</a> genannt.
</p><p>Ist die gegebene Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> zweimal <a href="Differenzierbarkeit" title="Differenzierbarkeit">differenzierbar</a>, so nimmt an einer Wendestelle die <a href="Steigung" title="Steigung">Steigung</a> des Funktionsgraphen, also die <a href="Differentialrechnung#Ableitungsfunktion" title="Differentialrechnung">Ableitung</a> <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'(x)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>′</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'(x)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3458cb314ea03925dc0986c31dfda5ed0857e6ee.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:5.489ex; height:3.009ex;" alt="{\displaystyle f\,'(x)}" loading="lazy"></span>, einen <a href="Extremwert" title="Extremwert">Extremwert</a> (ein lokales Minimum oder Maximum) an. Daher erfolgt die rechnerische Bestimmung von Wendestellen meist dadurch, dass man die zweite Ableitung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/43b10016ec610860e77d6e9cc0db92387e798505.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:5.942ex; height:3.009ex;" alt="{\displaystyle f\,''(x)}" loading="lazy"></span>, also die Ableitung der Ableitung, gleich null setzt. In Abschnitten mit Linkskrümmung gilt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x)>0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>&gt;</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x)&gt;0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/6a642981755834966f9e2921dd113fbcf1a870ae.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:10.203ex; height:3.009ex;" alt="{\displaystyle f\,''(x)>0}" loading="lazy"></span>, in Abschnitten mit Rechtskrümmung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x)<0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>&lt;</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x)&lt;0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/b7045f8c04e479aa783ec56d17ed5326122f070c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:10.203ex; height:3.009ex;" alt="{\displaystyle f\,''(x)<0}" loading="lazy"></span>. Genaueres ist den Ausführungen über notwendige und hinreichende Kriterien für Wendepunkte zu entnehmen.
</p>

<div class="mw-heading mw-heading2"><h2 id="Definition">Definition</h2></div>
<p>In der folgenden Definition werden die anschaulichen Begriffe „linksgekrümmt“ und „rechtsgekrümmt“ durch die entsprechenden exakten Begriffe „strikt konvex“ und „strikt konkav“ ersetzt.
</p><p>Sei <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {]a,b[}\subset \mathbb {R} }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">]</mo>
<mi>a</mi>
<mo>,</mo>
<mi>b</mi>
<mo stretchy="false">[</mo>
</mrow>
<mo>⊂<!-- ⊂ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="double-struck">R</mi>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {]a,b[}\subset \mathbb {R} }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/a7e0b2eb730f77194f71b92b704bbc7dcbd4467b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:9.332ex; height:2.843ex;" alt="{\displaystyle {]a,b[}\subset \mathbb {R} }" loading="lazy"></span> ein offenes <a href="Intervall_(Mathematik)" title="Intervall (Mathematik)">Intervall</a> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\colon {]a,b[}\to \mathbb {R} }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<mo>:<!-- : --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">]</mo>
<mi>a</mi>
<mo>,</mo>
<mi>b</mi>
<mo stretchy="false">[</mo>
</mrow>
<mo stretchy="false">→<!-- → --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="double-struck">R</mi>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\colon {]a,b[}\to \mathbb {R} }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/11d2c2898c603ff521c5682305b0fa89bedac063.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.16ex; height:2.843ex;" alt="{\displaystyle f\colon {]a,b[}\to \mathbb {R} }" loading="lazy"></span> eine <a href="Stetige_Funktion" title="Stetige Funktion">stetige Funktion</a>. <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> hat in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{0}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{0}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86f21d0e31751534cd6584264ecf864a6aa792cf.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.384ex; height:2.009ex;" alt="{\displaystyle x_{0}}" loading="lazy"></span> einen <i>Wendepunkt</i>, wenn es Intervalle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle ]\alpha ,x_{0}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">]</mo>
<mi>α<!-- α --></mi>
<mo>,</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle ]\alpha ,x_{0}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/25f9d4f71b5db53baabdb50c885f9222e2335004.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.199ex; height:2.843ex;" alt="{\displaystyle ]\alpha ,x_{0}[}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle ]x_{0},\beta [}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">]</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mi>β<!-- β --></mi>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle ]x_{0},\beta [}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/a973e19877c64cccf9ece3332d6ea38a8ebf5284.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.044ex; height:2.843ex;" alt="{\displaystyle ]x_{0},\beta [}" loading="lazy"></span> gibt, so dass entweder
</p>
<ul><li><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle ]\alpha ,x_{0}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">]</mo>
<mi>α<!-- α --></mi>
<mo>,</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle ]\alpha ,x_{0}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/25f9d4f71b5db53baabdb50c885f9222e2335004.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.199ex; height:2.843ex;" alt="{\displaystyle ]\alpha ,x_{0}[}" loading="lazy"></span> <a href="Konvexe_Funktion#Weitere_Klassifizierungen" class="mw-redirect" title="Konvexe Funktion">strikt konvex</a> und in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle ]x_{0},\beta [}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">]</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mi>β<!-- β --></mi>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle ]x_{0},\beta [}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/a973e19877c64cccf9ece3332d6ea38a8ebf5284.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.044ex; height:2.843ex;" alt="{\displaystyle ]x_{0},\beta [}" loading="lazy"></span> <a href="Konkave_Funktion#Weitere_Klassifizierungen" class="mw-redirect" title="Konkave Funktion">strikt konkav</a> oder</li>
<li><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle ]\alpha ,x_{0}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">]</mo>
<mi>α<!-- α --></mi>
<mo>,</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle ]\alpha ,x_{0}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/25f9d4f71b5db53baabdb50c885f9222e2335004.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.199ex; height:2.843ex;" alt="{\displaystyle ]\alpha ,x_{0}[}" loading="lazy"></span> strikt konkav und in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle ]x_{0},\beta [}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">]</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mi>β<!-- β --></mi>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle ]x_{0},\beta [}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/a973e19877c64cccf9ece3332d6ea38a8ebf5284.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.044ex; height:2.843ex;" alt="{\displaystyle ]x_{0},\beta [}" loading="lazy"></span> strikt konvex ist.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></li></ul>
<p>Bemerkung: In der Literatur werden teilweise statt der Eigenschaften „strikt konvex“ und „strikt konkav“ nur die schwächeren Eigenschaften „konvex“ und „konkav“ gefordert. Bei einer solchen Definition hätten z.&nbsp;B. die Graphen von linearen Funktionen (also Geraden) an jeder Stelle einen Wendepunkt.<sup id="cite_ref-Spektrum-Wendepunkt_2-0" class="reference"><a href="#cite_note-Spektrum-Wendepunkt-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>
</p>
<div class="mw-heading mw-heading2"><h2 id="Kriterien_zur_Bestimmung_von_Wendepunkten">Kriterien zur Bestimmung von Wendepunkten</h2></div>
<p>Im Folgenden wird vorausgesetzt, dass die Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\colon {]a,b[}\to \mathbb {R} }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<mo>:<!-- : --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">]</mo>
<mi>a</mi>
<mo>,</mo>
<mi>b</mi>
<mo stretchy="false">[</mo>
</mrow>
<mo stretchy="false">→<!-- → --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="double-struck">R</mi>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\colon {]a,b[}\to \mathbb {R} }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/11d2c2898c603ff521c5682305b0fa89bedac063.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.16ex; height:2.843ex;" alt="{\displaystyle f\colon {]a,b[}\to \mathbb {R} }" loading="lazy"></span> hinreichend oft differenzierbar ist. Andernfalls sind die folgenden Kriterien bei der Suche nach Wendepunkten nicht anwendbar. Zuerst wird ein notwendiges Kriterium vorgestellt, das heißt jede zweimal stetig differenzierbare Funktion muss dieses Kriterium an einer Stelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span> erfüllen, wenn der Graph dort einen Wendepunkt besitzt. Danach werden einige hinreichende Kriterien angegeben. Ist eines dieser Kriterien erfüllt, so liegt sicher ein Wendepunkt vor. Es kann jedoch bei jedem dieser hinreichenden Kriterien vorkommen, dass ein Wendepunkt dieses Kriterium nicht erfüllt.
</p>
<div class="mw-heading mw-heading3"><h3 id="Notwendiges_Kriterium">Notwendiges Kriterium</h3></div>
<p>Ist <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\colon {]a,b[}\to \mathbb {R} }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<mo>:<!-- : --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">]</mo>
<mi>a</mi>
<mo>,</mo>
<mi>b</mi>
<mo stretchy="false">[</mo>
</mrow>
<mo stretchy="false">→<!-- → --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="double-struck">R</mi>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\colon {]a,b[}\to \mathbb {R} }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/11d2c2898c603ff521c5682305b0fa89bedac063.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.16ex; height:2.843ex;" alt="{\displaystyle f\colon {]a,b[}\to \mathbb {R} }" loading="lazy"></span> eine zweimal differenzierbare Funktion, dann beschreibt die zweite Ableitung das Krümmungsverhalten des Funktionsgraphen. Da sich an einem Wendepunkt das Krümmungsverhalten ändert, muss die zweite Ableitung der Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> an diesem Punkt null sein.<sup id="cite_ref-Spektrum-Wendepunkt_2-1" class="reference"><a href="#cite_note-Spektrum-Wendepunkt-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \left.{\begin{array}{l}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ zweimal differenzierbar.}}\\x_{W}{\text{ ist Wendestelle.}}\end{array}}\right\}\Rightarrow f\,''(x_{W})=0.}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow>
<mo fence="true" stretchy="true" symmetric="true"></mo>
<mrow class="MJX-TeXAtom-ORD">
<mtable columnalign="left" rowspacing="4pt" columnspacing="1em">
<mtr>
<mtd>
<mi>f</mi>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;ist in einer Umgebung von&nbsp;</mtext>
</mrow>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;zweimal differenzierbar.</mtext>
</mrow>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;ist Wendestelle.</mtext>
</mrow>
</mtd>
</mtr>
</mtable>
</mrow>
<mo>}</mo>
</mrow>
<mo stretchy="false">⇒<!-- ⇒ --></mo>
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0.</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \left.{\begin{array}{l}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ zweimal differenzierbar.}}\\x_{W}{\text{ ist Wendestelle.}}\end{array}}\right\}\Rightarrow f\,''(x_{W})=0.}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/84399f507a8cbd2a0fe879465f77b88c7b5fd909.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:75.443ex; height:6.176ex;" alt="{\displaystyle \left.{\begin{array}{l}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ zweimal differenzierbar.}}\\x_{W}{\text{ ist Wendestelle.}}\end{array}}\right\}\Rightarrow f\,''(x_{W})=0.}" loading="lazy"></span></dd></dl>
<div class="mw-heading mw-heading3"><h3 id="Hinreichendes_Kriterium_ohne_Verwendung_der_dritten_Ableitung">Hinreichendes Kriterium ohne Verwendung der dritten Ableitung</h3></div>
<p>Bei Kurvendiskussionen wird in der Regel eine der beiden folgenden hinreichenden Bedingungen verwendet. In der ersten Bedingung kommt nur die zweite Ableitung vor; dafür muss das <a href="Vorzeichen_(Zahl)" title="Vorzeichen (Zahl)">Vorzeichen</a> von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/43b10016ec610860e77d6e9cc0db92387e798505.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:5.942ex; height:3.009ex;" alt="{\displaystyle f\,''(x)}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x<x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>&lt;</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x&lt;x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/a465b4635bcb9bb44e3c89c3ed02e72e1e8340fd.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:7.712ex; height:2.176ex;" alt="{\displaystyle x<x_{W}}" loading="lazy"></span> und für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x>x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>&gt;</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x&gt;x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/62e969c08769850b5923668da1e6456f528f56ce.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:7.712ex; height:2.176ex;" alt="{\displaystyle x>x_{W}}" loading="lazy"></span> untersucht werden.
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ zweimal differenzierbar.}}\\f\,''(x){\text{ wechselt an der Stelle }}x_{W}{\text{ das Vorzeichen.}}\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow>
<mo fence="true" stretchy="true" symmetric="true"></mo>
<mrow class="MJX-TeXAtom-ORD">
<mtable columnalign="left left" rowspacing="4pt" columnspacing="1em">
<mtr>
<mtd>
<mi>f</mi>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;ist in einer Umgebung von&nbsp;</mtext>
</mrow>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;zweimal differenzierbar.</mtext>
</mrow>
</mtd>
</mtr>
<mtr>
<mtd>
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;wechselt an der Stelle&nbsp;</mtext>
</mrow>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;das Vorzeichen.</mtext>
</mrow>
</mtd>
</mtr>
</mtable>
</mrow>
<mo>}</mo>
</mrow>
<mo stretchy="false">⇒<!-- ⇒ --></mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;ist Wendestelle.</mtext>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ zweimal differenzierbar.}}\\f\,''(x){\text{ wechselt an der Stelle }}x_{W}{\text{ das Vorzeichen.}}\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9eb4ac90e4f4b57bbcc059161f468434128999a6.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:82.417ex; height:6.176ex;" alt="{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ zweimal differenzierbar.}}\\f\,''(x){\text{ wechselt an der Stelle }}x_{W}{\text{ das Vorzeichen.}}\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}" loading="lazy"></span></dd></dl>
<p>Wechselt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f''(x)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mi>f</mi>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f''(x)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0e2e84959f7e6426747625eee3248602ef8b2e60.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:5.597ex; height:3.009ex;" alt="{\displaystyle f''(x)}" loading="lazy"></span> bei <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x=x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>=</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x=x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/28c17d8082b36943c75a49dc2ecf02fa02dadadc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:7.712ex; height:2.009ex;" alt="{\displaystyle x=x_{W}}" loading="lazy"></span> vom Negativen ins Positive, so ist <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span> eine „Rechts-links-Wendestelle“. Wenn <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f''(x)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mi>f</mi>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f''(x)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0e2e84959f7e6426747625eee3248602ef8b2e60.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:5.597ex; height:3.009ex;" alt="{\displaystyle f''(x)}" loading="lazy"></span> an dieser Stelle vom Positiven ins Negative wechselt, dann ist <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span> eine „Links-rechts-Wendestelle“.
</p>
<div class="mw-heading mw-heading3"><h3 id="Hinreichendes_Kriterium_unter_Verwendung_der_dritten_Ableitung">Hinreichendes Kriterium unter Verwendung der dritten Ableitung</h3></div>

<p>In der zweiten für einen Wendepunkt hinreichenden Bedingung wird auch die dritte Ableitung benötigt, allerdings nur an der Stelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span> selbst. Diese Bedingung wird vor allem dann verwendet, wenn die dritte Ableitung leicht zu ermitteln ist. Der Hauptnachteil gegenüber der schon erläuterten Bedingung liegt darin, dass im Falle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'''(x_{W})=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'''(x_{W})=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/31d85d8b36c90093c486b9a505a84b277f9a0918.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.609ex; height:3.009ex;" alt="{\displaystyle f\,'''(x_{W})=0}" loading="lazy"></span> keine Entscheidung getroffen werden kann.
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ dreimal differenzierbar.}}\\f\,''(x_{W})=0\\f\,'''(x_{W})\neq 0\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow>
<mo fence="true" stretchy="true" symmetric="true"></mo>
<mrow class="MJX-TeXAtom-ORD">
<mtable columnalign="left left" rowspacing="4pt" columnspacing="1em">
<mtr>
<mtd>
<mi>f</mi>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;ist in einer Umgebung von&nbsp;</mtext>
</mrow>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;dreimal differenzierbar.</mtext>
</mrow>
</mtd>
</mtr>
<mtr>
<mtd>
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mtd>
</mtr>
<mtr>
<mtd>
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>≠<!-- ≠ --></mo>
<mn>0</mn>
</mtd>
</mtr>
</mtable>
</mrow>
<mo>}</mo>
</mrow>
<mo stretchy="false">⇒<!-- ⇒ --></mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;ist Wendestelle.</mtext>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ dreimal differenzierbar.}}\\f\,''(x_{W})=0\\f\,'''(x_{W})\neq 0\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/03b9fe142736dcdf2114c4ab46fb2d4a5af5399f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -4.171ex; width:82.233ex; height:9.509ex;" alt="{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}{\text{ dreimal differenzierbar.}}\\f\,''(x_{W})=0\\f\,'''(x_{W})\neq 0\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}" loading="lazy"></span><sup id="cite_ref-Spektrum-Wendepunkt_2-2" class="reference"><a href="#cite_note-Spektrum-Wendepunkt-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup></dd></dl>
<p>Genauer folgt aus <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x_{W})=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x_{W})=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/1f03874abac43bc118abbda6e1257014b0605ed1.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.157ex; height:3.009ex;" alt="{\displaystyle f\,''(x_{W})=0}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'''(x_{W})>0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>&gt;</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'''(x_{W})&gt;0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8d9a8730c55d484289cb39a19380b7c077e7c1e2.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.609ex; height:3.009ex;" alt="{\displaystyle f\,'''(x_{W})>0}" loading="lazy"></span>, dass <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> bei <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span> ein Minimum des Anstiegs, also eine „Rechts-links-Wendestelle“ besitzt, während sie umgekehrt für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x_{W})=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x_{W})=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/1f03874abac43bc118abbda6e1257014b0605ed1.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.157ex; height:3.009ex;" alt="{\displaystyle f\,''(x_{W})=0}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'''(x_{W})<0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>&lt;</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'''(x_{W})&lt;0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/a61bbc79ab2385359dace5be13ce5a9bcc56071a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.609ex; height:3.009ex;" alt="{\displaystyle f\,'''(x_{W})<0}" loading="lazy"></span> bei <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span> ein Maximum des Anstiegs, also eine „Links-rechts-Wendestelle“ aufweist.
</p><p>Das Beispiel <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f(x)=x^{5}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>5</mn>
</mrow>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f(x)=x^{5}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e2cecea79ff6581f69118cd670ccb5a4b2552712.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:9.9ex; height:3.176ex;" alt="{\displaystyle f(x)=x^{5}}" loading="lazy"></span> zeigt, dass <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'''(x_{W})\neq 0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>≠<!-- ≠ --></mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'''(x_{W})\neq 0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3739f5547f867becdd47e2c021ec2a800e1c77e7.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.609ex; height:3.009ex;" alt="{\displaystyle f\,'''(x_{W})\neq 0}" loading="lazy"></span> keine notwendige Bedingung ist. Der Graph dieser Funktion hat den Wendepunkt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (0|0)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mn>0</mn>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">|</mo>
</mrow>
<mn>0</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (0|0)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/633c64e510877e575d450c70307e92697c121553.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:4.781ex; height:2.843ex;" alt="{\displaystyle (0|0)}" loading="lazy"></span>; trotzdem gilt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'''(0)=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<mn>0</mn>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'''(0)=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/69e90ea4e5d9e068b04056eb4148c10f8a2c490b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:10.488ex; height:3.009ex;" alt="{\displaystyle f\,'''(0)=0}" loading="lazy"></span>.
</p>
<div class="mw-heading mw-heading3"><h3 id="Hinreichendes_Kriterium_unter_Verwendung_weiterer_Ableitungen">Hinreichendes Kriterium unter Verwendung weiterer Ableitungen</h3></div>
<p>Ist die Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> hinreichend oft differenzierbar, kann auch im Falle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'''(x_{W})=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'''(x_{W})=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/31d85d8b36c90093c486b9a505a84b277f9a0918.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.609ex; height:3.009ex;" alt="{\displaystyle f\,'''(x_{W})=0}" loading="lazy"></span> eine Entscheidung getroffen werden. Dies basiert auf der Entwicklung von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> an der Stelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{0}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{0}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86f21d0e31751534cd6584264ecf864a6aa792cf.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.384ex; height:2.009ex;" alt="{\displaystyle x_{0}}" loading="lazy"></span> mittels der <a href="Taylor-Formel" title="Taylor-Formel">Taylor-Formel</a>:<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup>
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}\,n{\text{-mal differenzierbar.}}\\f\,''(x_{W})=\ldots =f\,^{(n-1)}(x_{W})=0\\f\,^{(n)}(x_{W})\neq 0\;{\text{ mit }}\,n>2\,{\text{und}}\,n\,{\text{ungerade}}\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow>
<mo fence="true" stretchy="true" symmetric="true"></mo>
<mrow class="MJX-TeXAtom-ORD">
<mtable columnalign="left left" rowspacing="4pt" columnspacing="1em">
<mtr>
<mtd>
<mi>f</mi>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;ist in einer Umgebung von&nbsp;</mtext>
</mrow>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mspace width="thinmathspace"></mspace>
<mi>n</mi>
<mrow class="MJX-TeXAtom-ORD">
<mtext>-mal differenzierbar.</mtext>
</mrow>
</mtd>
</mtr>
<mtr>
<mtd>
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mo>…<!-- … --></mo>
<mo>=</mo>
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">(</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mrow>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mtd>
</mtr>
<mtr>
<mtd>
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">(</mo>
<mi>n</mi>
<mo stretchy="false">)</mo>
</mrow>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>≠<!-- ≠ --></mo>
<mn>0</mn>
<mspace width="thickmathspace"></mspace>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;mit&nbsp;</mtext>
</mrow>
<mspace width="thinmathspace"></mspace>
<mi>n</mi>
<mo>&gt;</mo>
<mn>2</mn>
<mspace width="thinmathspace"></mspace>
<mrow class="MJX-TeXAtom-ORD">
<mtext>und</mtext>
</mrow>
<mspace width="thinmathspace"></mspace>
<mi>n</mi>
<mspace width="thinmathspace"></mspace>
<mrow class="MJX-TeXAtom-ORD">
<mtext>ungerade</mtext>
</mrow>
</mtd>
</mtr>
</mtable>
</mrow>
<mo>}</mo>
</mrow>
<mo stretchy="false">⇒<!-- ⇒ --></mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mtext>&nbsp;ist Wendestelle.</mtext>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}\,n{\text{-mal differenzierbar.}}\\f\,''(x_{W})=\ldots =f\,^{(n-1)}(x_{W})=0\\f\,^{(n)}(x_{W})\neq 0\;{\text{ mit }}\,n&gt;2\,{\text{und}}\,n\,{\text{ungerade}}\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/52645c6c97d00401ce93aab2dab60d33ba228dc4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -4.505ex; width:80.326ex; height:10.176ex;" alt="{\displaystyle \left.{\begin{array}{ll}f{\text{ ist in einer Umgebung von }}x_{W}\,n{\text{-mal differenzierbar.}}\\f\,''(x_{W})=\ldots =f\,^{(n-1)}(x_{W})=0\\f\,^{(n)}(x_{W})\neq 0\;{\text{ mit }}\,n>2\,{\text{und}}\,n\,{\text{ungerade}}\end{array}}\right\}\Rightarrow x_{W}{\text{ ist Wendestelle.}}}" loading="lazy"></span></dd></dl>
<p>Diese allgemeinere Formulierung enthält auch schon den vorangegangenen Fall: Beginnend mit der dritten Ableitung wird die nächste von Null verschiedene Ableitung gesucht, und falls dies eine Ableitung ungerader Ordnung ist, handelt es sich um eine Wendestelle.
</p><p>Oder ganz allgemein formuliert: Ist die erste von Null verschiedene Ableitung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f^{(n)}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mi>f</mi>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">(</mo>
<mi>n</mi>
<mo stretchy="false">)</mo>
</mrow>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f^{(n)}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9dfb1963ccde0e87eb3838f51dc19041e2ff3816.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.818ex; height:3.176ex;" alt="{\displaystyle f^{(n)}}" loading="lazy"></span> der Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> an der Stelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span>, an der <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f''(x_{W})=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mi>f</mi>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f''(x_{W})=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/4bbebf0b70a7512e2ec1521606e5db34a48434ad.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:11.812ex; height:3.009ex;" alt="{\displaystyle f''(x_{W})=0}" loading="lazy"></span> ist, von ungerader Ordnung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle n>2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>n</mi>
<mo>&gt;</mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle n&gt;2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/44e71ac55b9fbf1e9f341b946cda63d61d3ef2cd.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.656ex; height:2.176ex;" alt="{\displaystyle n>2}" loading="lazy"></span>, besitzt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> an dieser Stelle einen Wendepunkt.
</p>
<div class="mw-heading mw-heading2"><h2 id="Beispiel">Beispiel</h2></div>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f(x)={\frac {1}{3}}\cdot x^{3}-2\cdot x^{2}+3\cdot x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mn>1</mn>
<mn>3</mn>
</mfrac>
</mrow>
<mo>⋅<!-- ⋅ --></mo>
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>3</mn>
</mrow>
</msup>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mo>⋅<!-- ⋅ --></mo>
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msup>
<mo>+</mo>
<mn>3</mn>
<mo>⋅<!-- ⋅ --></mo>
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f(x)={\frac {1}{3}}\cdot x^{3}-2\cdot x^{2}+3\cdot x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/2a8cc774d1b761395cbfc940fab389728ab576e4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.838ex; width:28.655ex; height:5.176ex;" alt="{\displaystyle f(x)={\frac {1}{3}}\cdot x^{3}-2\cdot x^{2}+3\cdot x}" loading="lazy"></span></dd></dl>
<p>Die zweite Ableitung dieser Funktion ist gegeben durch
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x)=2\cdot x-4}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>2</mn>
<mo>⋅<!-- ⋅ --></mo>
<mi>x</mi>
<mo>−<!-- − --></mo>
<mn>4</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x)=2\cdot x-4}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/005d51b3a48f846856cc173af11658119d657252.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:17.214ex; height:3.009ex;" alt="{\displaystyle f\,''(x)=2\cdot x-4}" loading="lazy"></span>.</dd></dl>
<p>Eine Wendestelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/87f9e315fd7e2ba406057a97300593c4802b53e4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle x}" loading="lazy"></span> muss die Bedingung
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x)=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x)=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/053453175b8b3224ab0ce857ca6c1af6814cdf06.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:10.203ex; height:3.009ex;" alt="{\displaystyle f\,''(x)=0}" loading="lazy"></span> bzw.</dd>
<dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle 2\cdot x-4=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mn>2</mn>
<mo>⋅<!-- ⋅ --></mo>
<mi>x</mi>
<mo>−<!-- − --></mo>
<mn>4</mn>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle 2\cdot x-4=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e4033b17b9b97b8e890f72f4c497c0287ec77b59.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.505ex; width:12.435ex; height:2.343ex;" alt="{\displaystyle 2\cdot x-4=0}" loading="lazy"></span></dd></dl>
<p>erfüllen. Daraus folgt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x=2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>=</mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x=2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9f39b6e42e5ffb81ac7b051b9e48b9a91d0713c7.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.591ex; height:2.176ex;" alt="{\displaystyle x=2}" loading="lazy"></span>. Um zu klären, ob an dieser Stelle tatsächlich ein Wendepunkt vorliegt, untersucht man nun auch die dritte Ableitung:
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'''(x)=2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'''(x)=2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e6270f8f192f7604fc24476b4c519b1738972295.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:10.655ex; height:3.009ex;" alt="{\displaystyle f\,'''(x)=2}" loading="lazy"></span></dd></dl>
<p>Aus <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'''(2)=2\neq 0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>‴</mo>
</msup>
<mo stretchy="false">(</mo>
<mn>2</mn>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>2</mn>
<mo>≠<!-- ≠ --></mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'''(2)=2\neq 0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d52a1e8af578fe68291db1c0e1e32ed50543af3f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:14.749ex; height:3.009ex;" alt="{\displaystyle f\,'''(2)=2\neq 0}" loading="lazy"></span> ist zu schließen, dass es sich um einen Wendepunkt handelt. Diese Tatsache ist auch ohne Verwendung der dritten Ableitung zu erkennen: Wegen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x)=2\cdot x-4<0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>2</mn>
<mo>⋅<!-- ⋅ --></mo>
<mi>x</mi>
<mo>−<!-- − --></mo>
<mn>4</mn>
<mo>&lt;</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x)=2\cdot x-4&lt;0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/81a02655af29e5063ab34bd7bb5252e63762f41b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:21.475ex; height:3.009ex;" alt="{\displaystyle f\,''(x)=2\cdot x-4<0}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x<2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>&lt;</mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x&lt;2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3fe4c94bf3a8ff251787ffddfdbee18f32d14edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.591ex; height:2.176ex;" alt="{\displaystyle x<2}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x)=2\cdot x-4>0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>2</mn>
<mo>⋅<!-- ⋅ --></mo>
<mi>x</mi>
<mo>−<!-- − --></mo>
<mn>4</mn>
<mo>&gt;</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,''(x)=2\cdot x-4&gt;0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/47ffca0a98143baf3172f92370a380c069c4249f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:21.475ex; height:3.009ex;" alt="{\displaystyle f\,''(x)=2\cdot x-4>0}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x>2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>&gt;</mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x&gt;2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9f5baa43d43733ac518c4ba02435283386d87553.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.591ex; height:2.176ex;" alt="{\displaystyle x>2}" loading="lazy"></span> ändert sich das Krümmungsverhalten; daher muss ein Wendepunkt vorliegen.
</p><p>Die <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle y}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>y</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle y}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/b8a6208ec717213d4317e666f1ae872e00620a0d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.155ex; height:2.009ex;" alt="{\displaystyle y}" loading="lazy"></span>-Koordinate dieses Wendepunkts erhält man durch Einsetzen von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}=2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo>=</mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}=2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/6e49080d02f55d721941b38fa22e8334ea3c4f71.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:7.545ex; height:2.509ex;" alt="{\displaystyle x_{W}=2}" loading="lazy"></span> in die Funktionsgleichung.
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle y_{W}=f(2)={\frac {1}{3}}\cdot 2^{3}-2\cdot 2^{2}+3\cdot 2={\frac {2}{3}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>y</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
<mo>=</mo>
<mi>f</mi>
<mo stretchy="false">(</mo>
<mn>2</mn>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mn>1</mn>
<mn>3</mn>
</mfrac>
</mrow>
<mo>⋅<!-- ⋅ --></mo>
<msup>
<mn>2</mn>
<mrow class="MJX-TeXAtom-ORD">
<mn>3</mn>
</mrow>
</msup>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mo>⋅<!-- ⋅ --></mo>
<msup>
<mn>2</mn>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msup>
<mo>+</mo>
<mn>3</mn>
<mo>⋅<!-- ⋅ --></mo>
<mn>2</mn>
<mo>=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mn>2</mn>
<mn>3</mn>
</mfrac>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle y_{W}=f(2)={\frac {1}{3}}\cdot 2^{3}-2\cdot 2^{2}+3\cdot 2={\frac {2}{3}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/7240e8c300456e3d1d1d4130229e8f4cd42113d7.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.838ex; width:39.275ex; height:5.176ex;" alt="{\displaystyle y_{W}=f(2)={\frac {1}{3}}\cdot 2^{3}-2\cdot 2^{2}+3\cdot 2={\frac {2}{3}}}" loading="lazy"></span></dd></dl>
<p>Soll auch die Wendetangente bestimmt werden, so berechnet man zunächst deren Steigung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle m}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>m</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle m}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0a07d98bb302f3856cbabc47b2b9016692e3f7bc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:2.04ex; height:1.676ex;" alt="{\displaystyle m}" loading="lazy"></span>, und zwar durch Einsetzen der <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/87f9e315fd7e2ba406057a97300593c4802b53e4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle x}" loading="lazy"></span>-Koordinate in die Gleichung der ersten Ableitung.
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,'(x)=x^{2}-4\cdot x+3}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>′</mo>
</msup>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msup>
<mo>−<!-- − --></mo>
<mn>4</mn>
<mo>⋅<!-- ⋅ --></mo>
<mi>x</mi>
<mo>+</mo>
<mn>3</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f\,'(x)=x^{2}-4\cdot x+3}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/39a3d7afc9fdddfec31b33f13c818a6b367f72fb.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:21.986ex; height:3.176ex;" alt="{\displaystyle f\,'(x)=x^{2}-4\cdot x+3}" loading="lazy"></span></dd>
<dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle m=f\,'(2)=2^{2}-4\cdot 2+3=-1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>m</mi>
<mo>=</mo>
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>′</mo>
</msup>
<mo stretchy="false">(</mo>
<mn>2</mn>
<mo stretchy="false">)</mo>
<mo>=</mo>
<msup>
<mn>2</mn>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msup>
<mo>−<!-- − --></mo>
<mn>4</mn>
<mo>⋅<!-- ⋅ --></mo>
<mn>2</mn>
<mo>+</mo>
<mn>3</mn>
<mo>=</mo>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle m=f\,'(2)=2^{2}-4\cdot 2+3=-1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8d4d82dfe4d031ae2a0ca18016a034b2521a1e94.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:32.692ex; height:3.176ex;" alt="{\displaystyle m=f\,'(2)=2^{2}-4\cdot 2+3=-1}" loading="lazy"></span></dd></dl>
<p>Anschließend kann man die Steigung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle m}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>m</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle m}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0a07d98bb302f3856cbabc47b2b9016692e3f7bc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:2.04ex; height:1.676ex;" alt="{\displaystyle m}" loading="lazy"></span> sowie die Koordinaten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f2de0f7111f45de752c8e540ea8e9a22dc533336.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.284ex; height:2.009ex;" alt="{\displaystyle x_{W}}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle y_{W}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>y</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>W</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle y_{W}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/7d478606d5878ae7463c87b0064b38b42fa33b07.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.093ex; height:2.009ex;" alt="{\displaystyle y_{W}}" loading="lazy"></span> in die Geradengleichung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle y=m\cdot x+b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>y</mi>
<mo>=</mo>
<mi>m</mi>
<mo>⋅<!-- ⋅ --></mo>
<mi>x</mi>
<mo>+</mo>
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle y=m\cdot x+b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d60bb4112dea04e1ab376700547d67138155f88b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:13.141ex; height:2.509ex;" alt="{\displaystyle y=m\cdot x+b}" loading="lazy"></span> einsetzen.
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\frac {2}{3}}=(-1)\cdot 2+b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mn>2</mn>
<mn>3</mn>
</mfrac>
</mrow>
<mo>=</mo>
<mo stretchy="false">(</mo>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
<mo>⋅<!-- ⋅ --></mo>
<mn>2</mn>
<mo>+</mo>
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\frac {2}{3}}=(-1)\cdot 2+b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/b4c3965c509e4f2d83bb2401282acd156d369a70.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.838ex; width:16.556ex; height:5.176ex;" alt="{\displaystyle {\frac {2}{3}}=(-1)\cdot 2+b}" loading="lazy"></span></dd>
<dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b={\frac {8}{3}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
<mo>=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mn>8</mn>
<mn>3</mn>
</mfrac>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b={\frac {8}{3}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/2816c3182db238c0daf976a517fb612a18a7fc4a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.838ex; width:6.095ex; height:5.176ex;" alt="{\displaystyle b={\frac {8}{3}}}" loading="lazy"></span></dd></dl>
<p>Die Wendetangente hat demnach die Gleichung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle y=-x+{\frac {8}{3}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>y</mi>
<mo>=</mo>
<mo>−<!-- − --></mo>
<mi>x</mi>
<mo>+</mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mn>8</mn>
<mn>3</mn>
</mfrac>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle y=-x+{\frac {8}{3}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/2bd46b97b4af213346fe6cb4fce73ad5a48beb24.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.838ex; width:12.231ex; height:5.176ex;" alt="{\displaystyle y=-x+{\frac {8}{3}}}" loading="lazy"></span>.
</p>
<div class="mw-heading mw-heading2"><h2 id="Besondere_Fälle"><span id="Besondere_F.C3.A4lle"></span>Besondere Fälle</h2></div>
<ul><li>Der Graph der Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f(x)=(x-2)\cdot e^{|x|}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mo stretchy="false">)</mo>
<mo>⋅<!-- ⋅ --></mo>
<msup>
<mi>e</mi>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">|</mo>
</mrow>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">|</mo>
</mrow>
</mrow>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f(x)=(x-2)\cdot e^{|x|}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/510b236bd3458dbf4d30dcf53ce3fa5ed2e264e3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:19.508ex; height:3.343ex;" alt="{\displaystyle f(x)=(x-2)\cdot e^{|x|}}" loading="lazy"></span> ändert bei <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/953917eaf52f2e1baad54c8c9e3d6f9bb3710cdc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.591ex; height:2.176ex;" alt="{\displaystyle x=0}" loading="lazy"></span> sein Krümmungsverhalten (Übergang von Rechts- in Linkskrümmung). Die erste Ableitung an der Stelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/953917eaf52f2e1baad54c8c9e3d6f9bb3710cdc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.591ex; height:2.176ex;" alt="{\displaystyle x=0}" loading="lazy"></span> existiert nicht, wie am „Knick“ des Graphen erkennbar ist. Damit ist der obige Formalismus nicht anwendbar. Dennoch hat die Funktion hier einen Wendepunkt, nämlich <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (0|\!-\!2)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mn>0</mn>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">|</mo>
</mrow>
<mspace width="negativethinmathspace"></mspace>
<mo>−<!-- − --></mo>
<mspace width="negativethinmathspace"></mspace>
<mn>2</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (0|\!-\!2)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5716475e6e63a2ec22da706da1aa4eda104928df.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.847ex; height:2.843ex;" alt="{\displaystyle (0|\!-\!2)}" loading="lazy"></span>.</li></ul>
<ul><li>Der Graph der Funktion</li></ul>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x\mapsto x|x|={\begin{cases}-x^{2},&amp;{\text{falls}}\;x<0\\x^{2},&amp;{\text{falls}}\;x\geq 0\end{cases}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo stretchy="false">↦<!-- ↦ --></mo>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">|</mo>
</mrow>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">|</mo>
</mrow>
<mo>=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow>
<mo>{</mo>
<mtable columnalign="left left" rowspacing=".2em" columnspacing="1em" displaystyle="false">
<mtr>
<mtd>
<mo>−<!-- − --></mo>
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
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<mo>,</mo>
</mtd>
<mtd>
<mrow class="MJX-TeXAtom-ORD">
<mtext>falls</mtext>
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<mspace width="thickmathspace"></mspace>
<mi>x</mi>
<mo>&lt;</mo>
<mn>0</mn>
</mtd>
</mtr>
<mtr>
<mtd>
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
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</msup>
<mo>,</mo>
</mtd>
<mtd>
<mrow class="MJX-TeXAtom-ORD">
<mtext>falls</mtext>
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<mspace width="thickmathspace"></mspace>
<mi>x</mi>
<mo>≥<!-- ≥ --></mo>
<mn>0</mn>
</mtd>
</mtr>
</mtable>
<mo fence="true" stretchy="true" symmetric="true"></mo>
</mrow>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x\mapsto x|x|={\begin{cases}-x^{2},&amp;{\text{falls}}\;x&lt;0\\x^{2},&amp;{\text{falls}}\;x\geq 0\end{cases}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f94ff35110aa0de7013d86386271831aff98e7ea.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:31.971ex; height:6.176ex;" alt="{\displaystyle x\mapsto x|x|={\begin{cases}-x^{2},&amp;{\text{falls}}\;x<0\\x^{2},&amp;{\text{falls}}\;x\geq 0\end{cases}}}" loading="lazy"></span></dd></dl>
<p>hat an der Stelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/953917eaf52f2e1baad54c8c9e3d6f9bb3710cdc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.591ex; height:2.176ex;" alt="{\displaystyle x=0}" loading="lazy"></span> zwar eine erste, aber keine zweite Ableitung, gleichwohl liegt ein Wendepunkt vor.
</p>
<ul><li>Der Graph der unendlich oft differenzierbaren Funktion</li></ul>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x\mapsto {\begin{cases}-\mathrm {e} ^{-1/x^{2}},&amp;{\text{falls}}\;x<0\\0,&amp;{\text{falls}}\;x=0\\\mathrm {e} ^{-1/x^{2}},&amp;{\text{falls}}\;x>0\end{cases}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo stretchy="false">↦<!-- ↦ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow>
<mo>{</mo>
<mtable columnalign="left left" rowspacing=".2em" columnspacing="1em" displaystyle="false">
<mtr>
<mtd>
<mo>−<!-- − --></mo>
<msup>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="normal">e</mi>
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<mrow class="MJX-TeXAtom-ORD">
<mo>−<!-- − --></mo>
<mn>1</mn>
<mrow class="MJX-TeXAtom-ORD">
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<mrow class="MJX-TeXAtom-ORD">
<mtext>falls</mtext>
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<mspace width="thickmathspace"></mspace>
<mi>x</mi>
<mo>&lt;</mo>
<mn>0</mn>
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<mtr>
<mtd>
<mn>0</mn>
<mo>,</mo>
</mtd>
<mtd>
<mrow class="MJX-TeXAtom-ORD">
<mtext>falls</mtext>
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<mspace width="thickmathspace"></mspace>
<mi>x</mi>
<mo>=</mo>
<mn>0</mn>
</mtd>
</mtr>
<mtr>
<mtd>
<msup>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="normal">e</mi>
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<mrow class="MJX-TeXAtom-ORD">
<mo>−<!-- − --></mo>
<mn>1</mn>
<mrow class="MJX-TeXAtom-ORD">
<mo>/</mo>
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<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
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</msup>
<mo>,</mo>
</mtd>
<mtd>
<mrow class="MJX-TeXAtom-ORD">
<mtext>falls</mtext>
</mrow>
<mspace width="thickmathspace"></mspace>
<mi>x</mi>
<mo>&gt;</mo>
<mn>0</mn>
</mtd>
</mtr>
</mtable>
<mo fence="true" stretchy="true" symmetric="true"></mo>
</mrow>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x\mapsto {\begin{cases}-\mathrm {e} ^{-1/x^{2}},&amp;{\text{falls}}\;x&lt;0\\0,&amp;{\text{falls}}\;x=0\\\mathrm {e} ^{-1/x^{2}},&amp;{\text{falls}}\;x&gt;0\end{cases}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/dea5e044c85dfcc279af827c0f1104a079e67e6c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -4.171ex; width:28.818ex; height:9.343ex;" alt="{\displaystyle x\mapsto {\begin{cases}-\mathrm {e} ^{-1/x^{2}},&amp;{\text{falls}}\;x<0\\0,&amp;{\text{falls}}\;x=0\\\mathrm {e} ^{-1/x^{2}},&amp;{\text{falls}}\;x>0\end{cases}}}" loading="lazy"></span></dd></dl>
<p>besitzt an der Stelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/953917eaf52f2e1baad54c8c9e3d6f9bb3710cdc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.591ex; height:2.176ex;" alt="{\displaystyle x=0}" loading="lazy"></span> einen Wendepunkt, obwohl dort sämtliche Ableitungen gleich null sind.
</p>
<div class="mw-heading mw-heading2"><h2 id="Verallgemeinerung">Verallgemeinerung</h2></div>
<p>Der Begriff des Wendepunkts ist auch für beliebige ebene <a href="Kurve_(Mathematik)" title="Kurve (Mathematik)">Kurven</a> sinnvoll. In der <a href="Differentialgeometrie" title="Differentialgeometrie">Differentialgeometrie</a> wird für ebene Kurven die vorzeichenbehaftete <a href="Kr%C3%BCmmung" title="Krümmung">Krümmung</a> definiert. Wendepunkte sind dadurch gekennzeichnet, dass sich dort das Vorzeichen der Krümmung umkehrt. Aus den – je nach Darstellung verschiedenen – Formeln für die Krümmung ergeben sich notwendige Kriterien für Wendepunkte. Die Aufstellung hinreichender Kriterien wäre hier wenig sinnvoll. In der Praxis ermittelt man mit einem der notwendigen Kriterien die Punkte, die als Wendepunkte in Frage kommen, und überprüft anschließend, ob sich das Vorzeichen der Krümmung wirklich ändert.
</p>
<div class="mw-heading mw-heading3"><h3 id="Wendepunkt_einer_Kurve_in_Parameterdarstellung">Wendepunkt einer Kurve in Parameterdarstellung</h3></div>
<p>Eine Kurve sei gegeben durch die Parameterdarstellung
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\vec {r}}(t)=(x(t),y(t)),}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>r</mi>
<mo stretchy="false">→<!-- → --></mo>
</mover>
</mrow>
</mrow>
<mo stretchy="false">(</mo>
<mi>t</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">(</mo>
<mi>t</mi>
<mo stretchy="false">)</mo>
<mo>,</mo>
<mi>y</mi>
<mo stretchy="false">(</mo>
<mi>t</mi>
<mo stretchy="false">)</mo>
<mo stretchy="false">)</mo>
<mo>,</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\vec {r}}(t)=(x(t),y(t)),}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e74fba9e3c8076d9d152686f68855afc33aaa154.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:18.244ex; height:2.843ex;" alt="{\displaystyle {\vec {r}}(t)=(x(t),y(t)),}" loading="lazy"></span></dd></dl>
<p>wobei die Funktionen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/87f9e315fd7e2ba406057a97300593c4802b53e4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle x}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle y}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>y</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle y}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/b8a6208ec717213d4317e666f1ae872e00620a0d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.155ex; height:2.009ex;" alt="{\displaystyle y}" loading="lazy"></span> auf einem reellen Intervall <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle I}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>I</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle I}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/535ea7fc4134a31cbe2251d9d3511374bc41be9f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.172ex; height:2.176ex;" alt="{\displaystyle I}" loading="lazy"></span> definiert und (mindestens) zweimal stetig differenzierbar sind. <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle t_{0}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>t</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle t_{0}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/02d3006c4190b1939b04d9b9bb21006fb4e6fa4a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.894ex; height:2.343ex;" alt="{\displaystyle t_{0}}" loading="lazy"></span> sei ein Punkt im Inneren des Intervalls <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle I}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>I</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle I}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/535ea7fc4134a31cbe2251d9d3511374bc41be9f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.172ex; height:2.176ex;" alt="{\displaystyle I}" loading="lazy"></span>.
Dann ist
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\begin{vmatrix}{\dot {x}}(t_{0})&amp;{\dot {y}}(t_{0})\\{\ddot {x}}(t_{0})&amp;{\ddot {y}}(t_{0})\end{vmatrix}}={\dot {x}}(t_{0})\cdot {\ddot {y}}(t_{0})-{\ddot {x}}(t_{0})\cdot {\dot {y}}(t_{0})=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow>
<mo>|</mo>
<mtable rowspacing="4pt" columnspacing="1em">
<mtr>
<mtd>
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<mrow class="MJX-TeXAtom-ORD">
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<mo>˙<!-- ˙ --></mo>
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<mo>˙<!-- ˙ --></mo>
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<mo>|</mo>
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<mi>x</mi>
<mo>˙<!-- ˙ --></mo>
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<mo stretchy="false">(</mo>
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</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>⋅<!-- ⋅ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>y</mi>
<mo>¨<!-- ¨ --></mo>
</mover>
</mrow>
</mrow>
<mo stretchy="false">(</mo>
<msub>
<mi>t</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>−<!-- − --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>x</mi>
<mo>¨<!-- ¨ --></mo>
</mover>
</mrow>
</mrow>
<mo stretchy="false">(</mo>
<msub>
<mi>t</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>⋅<!-- ⋅ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>y</mi>
<mo>˙<!-- ˙ --></mo>
</mover>
</mrow>
</mrow>
<mo stretchy="false">(</mo>
<msub>
<mi>t</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\begin{vmatrix}{\dot {x}}(t_{0})&amp;{\dot {y}}(t_{0})\\{\ddot {x}}(t_{0})&amp;{\ddot {y}}(t_{0})\end{vmatrix}}={\dot {x}}(t_{0})\cdot {\ddot {y}}(t_{0})-{\ddot {x}}(t_{0})\cdot {\dot {y}}(t_{0})=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/4753444a173620c9e7431eebfb16e1914560a525.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:48.04ex; height:6.176ex;" alt="{\displaystyle {\begin{vmatrix}{\dot {x}}(t_{0})&amp;{\dot {y}}(t_{0})\\{\ddot {x}}(t_{0})&amp;{\ddot {y}}(t_{0})\end{vmatrix}}={\dot {x}}(t_{0})\cdot {\ddot {y}}(t_{0})-{\ddot {x}}(t_{0})\cdot {\dot {y}}(t_{0})=0}" loading="lazy"></span></dd></dl>
<p>eine notwendige Bedingung für einen Wendepunkt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (x(t_{0}),y(t_{0}))}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">(</mo>
<msub>
<mi>t</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>,</mo>
<mi>y</mi>
<mo stretchy="false">(</mo>
<msub>
<mi>t</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (x(t_{0}),y(t_{0}))}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/1bf364c597fea6ab6d4601e34bfcb6a965f3a927.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.735ex; height:2.843ex;" alt="{\displaystyle (x(t_{0}),y(t_{0}))}" loading="lazy"></span>.<sup id="cite_ref-Bronstein-257_4-0" class="reference"><a href="#cite_note-Bronstein-257-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> Die Punkte über den Funktionssymbolen stehen für erste bzw. zweite Ableitungen nach dem Parameter <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle t}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>t</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle t}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/65658b7b223af9e1acc877d848888ecdb4466560.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.84ex; height:2.009ex;" alt="{\displaystyle t}" loading="lazy"></span>. Der Rechenausdruck links vom ersten Gleichheitszeichen ist eine <a href="Determinante" title="Determinante">Determinante</a>.
</p>
<div class="mw-heading mw-heading3"><h3 id="Wendepunkt_einer_Kurve_in_Polarkoordinaten">Wendepunkt einer Kurve in Polarkoordinaten</h3></div>
<p>Eine Kurve sei in <a href="Polarkoordinaten" title="Polarkoordinaten">Polarkoordinaten</a> gegeben durch die Gleichung
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle r=\rho (\varphi ),}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>r</mi>
<mo>=</mo>
<mi>ρ<!-- ρ --></mi>
<mo stretchy="false">(</mo>
<mi>φ<!-- φ --></mi>
<mo stretchy="false">)</mo>
<mo>,</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle r=\rho (\varphi ),}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/b4f9c1a2277e5bec6a975d9b05ec7dc9627d3bba.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:9.325ex; height:2.843ex;" alt="{\displaystyle r=\rho (\varphi ),}" loading="lazy"></span></dd></dl>
<p>wobei <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \rho }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>ρ<!-- ρ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \rho }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/1f7d439671d1289b6a816e6af7a304be40608d64.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:1.202ex; height:2.176ex;" alt="{\displaystyle \rho }" loading="lazy"></span> eine zweimal stetig differenzierbare Funktion auf einem reellen Intervall ist. Dann ist
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \rho ^{2}+2{\rho '}^{2}-\rho \rho ''=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mi>ρ<!-- ρ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msup>
<mo>+</mo>
<mn>2</mn>
<msup>
<mrow class="MJX-TeXAtom-ORD">
<msup>
<mi>ρ<!-- ρ --></mi>
<mo>′</mo>
</msup>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msup>
<mo>−<!-- − --></mo>
<mi>ρ<!-- ρ --></mi>
<msup>
<mi>ρ<!-- ρ --></mi>
<mo>″</mo>
</msup>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \rho ^{2}+2{\rho '}^{2}-\rho \rho ''=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0dd4240430784b849f77a3977177691de611378d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:19.842ex; height:3.509ex;" alt="{\displaystyle \rho ^{2}+2{\rho '}^{2}-\rho \rho ''=0}" loading="lazy"></span></dd></dl>
<p>eine notwendige Bedingung für einen Wendepunkt.<sup id="cite_ref-Bronstein-257_4-1" class="reference"><a href="#cite_note-Bronstein-257-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \rho '}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mi>ρ<!-- ρ --></mi>
<mo>′</mo>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \rho '}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e2400eb83af71f78fcb442e55bf294cebdfb9803.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:1.887ex; height:3.009ex;" alt="{\displaystyle \rho '}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \rho ''}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mi>ρ<!-- ρ --></mi>
<mo>″</mo>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \rho ''}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d633556808dad50c7af5ccd031c168b8d0dca0e0.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:2.339ex; height:3.009ex;" alt="{\displaystyle \rho ''}" loading="lazy"></span> bezeichnen die erste bzw. zweite Ableitung von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \rho }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>ρ<!-- ρ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \rho }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/1f7d439671d1289b6a816e6af7a304be40608d64.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:1.202ex; height:2.176ex;" alt="{\displaystyle \rho }" loading="lazy"></span> nach <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \varphi }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>φ<!-- φ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \varphi }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/33ee699558d09cf9d653f6351f9fda0b2f4aaa3e.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:1.52ex; height:2.176ex;" alt="{\displaystyle \varphi }" loading="lazy"></span>. Die Argumente wurden zur Vereinfachung der Schreibweise weggelassen.
</p>
<div class="mw-heading mw-heading3"><h3 id="Wendepunkt_einer_Kurve_in_impliziter_Form">Wendepunkt einer Kurve in impliziter Form</h3></div>
<p>Eine Kurve sei gegeben durch die Gleichung
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle F(x,y)=0,}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>F</mi>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo>,</mo>
<mi>y</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle F(x,y)=0,}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/23114792c399e36883fae6a06fcf7d34a3cb65e3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:11.977ex; height:2.843ex;" alt="{\displaystyle F(x,y)=0,}" loading="lazy"></span></dd></dl>
<p>wobei <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle F}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>F</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle F}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/545fd099af8541605f7ee55f08225526be88ce57.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.741ex; height:2.176ex;" alt="{\displaystyle F}" loading="lazy"></span> eine zweimal stetig differenzierbare Funktion auf einer <a href="Offene_Menge" title="Offene Menge">offenen Menge</a> des <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \mathbb {R} ^{2}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="double-struck">R</mi>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \mathbb {R} ^{2}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e150115ab9f63023215109595b76686a1ff890fd.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:2.732ex; height:2.676ex;" alt="{\displaystyle \mathbb {R} ^{2}}" loading="lazy"></span> ist.
Dann ist
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\begin{vmatrix}F_{xx}&amp;F_{xy}&amp;F_{x}\\F_{yx}&amp;F_{yy}&amp;F_{y}\\F_{x}&amp;F_{y}&amp;0\end{vmatrix}}=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow>
<mo>|</mo>
<mtable rowspacing="4pt" columnspacing="1em">
<mtr>
<mtd>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>x</mi>
<mi>x</mi>
</mrow>
</msub>
</mtd>
<mtd>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>x</mi>
<mi>y</mi>
</mrow>
</msub>
</mtd>
<mtd>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>x</mi>
</mrow>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>y</mi>
<mi>x</mi>
</mrow>
</msub>
</mtd>
<mtd>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>y</mi>
<mi>y</mi>
</mrow>
</msub>
</mtd>
<mtd>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>y</mi>
</mrow>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>x</mi>
</mrow>
</msub>
</mtd>
<mtd>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>y</mi>
</mrow>
</msub>
</mtd>
<mtd>
<mn>0</mn>
</mtd>
</mtr>
</mtable>
<mo>|</mo>
</mrow>
</mrow>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\begin{vmatrix}F_{xx}&amp;F_{xy}&amp;F_{x}\\F_{yx}&amp;F_{yy}&amp;F_{y}\\F_{x}&amp;F_{y}&amp;0\end{vmatrix}}=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9001bcb426b568da941a22b3a4bd762841f0a8dc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -4.338ex; width:20.71ex; height:9.843ex;" alt="{\displaystyle {\begin{vmatrix}F_{xx}&amp;F_{xy}&amp;F_{x}\\F_{yx}&amp;F_{yy}&amp;F_{y}\\F_{x}&amp;F_{y}&amp;0\end{vmatrix}}=0}" loading="lazy"></span></dd></dl>
<p>eine notwendige Bedingung für einen Wendepunkt.<sup id="cite_ref-Bronstein-257_4-2" class="reference"><a href="#cite_note-Bronstein-257-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> Die Bezeichnungen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle F_{x},F_{y},F_{xx},F_{xy},F_{yx},F_{yy}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>x</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>y</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>x</mi>
<mi>x</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>x</mi>
<mi>y</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>y</mi>
<mi>x</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>F</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>y</mi>
<mi>y</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle F_{x},F_{y},F_{xx},F_{xy},F_{yx},F_{yy}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c14b8cb6a332dcba92e058666181f45c4de7d998.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:24.317ex; height:2.843ex;" alt="{\displaystyle F_{x},F_{y},F_{xx},F_{xy},F_{yx},F_{yy}}" loading="lazy"></span> stehen dabei für erste bzw. zweite <a href="Partielle_Ableitung" title="Partielle Ableitung">partielle Ableitungen</a>. Auch hier wurden die Argumente weggelassen.
</p>
<div class="mw-heading mw-heading2"><h2 id="Siehe_auch">Siehe auch</h2></div>
<ul><li><a href="Flachpunkt" title="Flachpunkt">Flachpunkt</a>, ein Punkt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (x_{0}|f(x_{0}))}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">|</mo>
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<msub>
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<mo stretchy="false">)</mo>
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<annotation encoding="application/x-tex">{\displaystyle (x_{0}|f(x_{0}))}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e5265d3ef3d9a2c3ce3b630676fc3347be22713d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:10.312ex; height:2.843ex;" alt="{\displaystyle (x_{0}|f(x_{0}))}" loading="lazy"></span>, an dem <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x_{0})=0}">
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<mi>f</mi>
<msup>
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<annotation encoding="application/x-tex">{\displaystyle f\,''(x_{0})=0}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/90ec01f61a10991fd6d1ac602cd07117bfcd60b0.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:11.257ex; height:3.009ex;" alt="{\displaystyle f\,''(x_{0})=0}" loading="lazy"></span> gilt (bzw. an dem <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f\,''(x_{0})=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
<msup>
<mspace width="thinmathspace"></mspace>
<mo>″</mo>
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<mo>=</mo>
<mn>0</mn>
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<annotation encoding="application/x-tex">{\displaystyle f\,''(x_{0})=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/90ec01f61a10991fd6d1ac602cd07117bfcd60b0.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:11.257ex; height:3.009ex;" alt="{\displaystyle f\,''(x_{0})=0}" loading="lazy"></span> gilt, aber sich das Krümmungsverhalten nicht ändert – je nach Definition)</li></ul>
<div class="mw-heading mw-heading2"><h2 id="Literatur">Literatur</h2></div>
<ul><li><a href="Harro_Heuser" title="Harro Heuser">Harro Heuser</a>: <i>Lehrbuch der <a href="Analysis" title="Analysis">Analysis</a>, Teil 1</i>. 11. Auflage, S. 293.</li></ul>
<div class="mw-heading mw-heading2"><h2 id="Weblinks">Weblinks</h2></div>
<div class="sisterproject" style="margin:0.1em 0 0 0;"><span class="noviewer" style="display:inline-block; line-height:10px; min-width:1.6em; text-align:center;" aria-hidden="true" role="presentation"><span class="mw-default-size" typeof="mw:File"><span title="Wiktionary"></span></span></span><b><a href="https://de.wiktionary.org/wiki/Wendepunkt" class="extiw external" title="wikt:Wendepunkt">Wiktionary: Wendepunkt</a></b>&nbsp;– Bedeutungserklärungen, Wortherkunft, Synonyme, Übersetzungen</div>
<div class="mw-heading mw-heading2"><h2 id="Einzelnachweise">Einzelnachweise</h2></div>
<ol class="references">
<li id="cite_note-1"><span class="mw-cite-backlink"><a href="#cite_ref-1">↑</a></span> <span class="reference-text">Konrad Königsberger: <cite style="font-style:italic">Analysis. 1</cite>. 6. Auflage. Springer, Berlin 2004, ISBN 3-540-40371-X, <span style="white-space:nowrap">S.<span style="display:inline-block;width:.2em">&nbsp;</span>159</span>.<span class="Z3988" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rfr_id=info:sid/de.wikipedia.org:Wendepunkt&amp;rft.au=Konrad+K%C3%B6nigsberger&amp;rft.btitle=Analysis.+1&amp;rft.date=2004&amp;rft.edition=6.&amp;rft.genre=book&amp;rft.isbn=354040371X&amp;rft.pages=159&amp;rft.place=Berlin&amp;rft.pub=Springer" style="display:none">&nbsp;</span></span>
</li>
<li id="cite_note-Spektrum-Wendepunkt-2"><span class="mw-cite-backlink">↑ <sup><a href="#cite_ref-Spektrum-Wendepunkt_2-0">a</a></sup> <sup><a href="#cite_ref-Spektrum-Wendepunkt_2-1">b</a></sup> <sup><a href="#cite_ref-Spektrum-Wendepunkt_2-2">c</a></sup></span> <span class="reference-text"><cite style="font-style:italic">Wendepunkt</cite>. In: Guido Walz (Hrsg.): <cite style="font-style:italic">Lexikon der Mathematik</cite>. <span style="white-space:nowrap">Band<span style="display:inline-block;width:.2em">&nbsp;</span>5</span>. Spektrum Akademischer Verlag, Heidelberg 2002, ISBN 3-8274-0437-1, <span style="white-space:nowrap">S.<span style="display:inline-block;width:.2em">&nbsp;</span>401–402</span> (<a rel="nofollow" class="external text" href="https://www.spektrum.de/lexikon/mathematik/wendepunkt/10934">spektrum.de</a> [abgerufen am 11.&nbsp;Januar 2025]).<span class="Z3988" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rfr_id=info:sid/de.wikipedia.org:Wendepunkt&amp;rft.atitle=Wendepunkt&amp;rft.btitle=Lexikon+der+Mathematik&amp;rft.date=2002&amp;rft.genre=book&amp;rft.isbn=3827404371&amp;rft.pages=401-402&amp;rft.place=Heidelberg&amp;rft.pub=Spektrum+Akademischer+Verlag&amp;rft.volume=5" style="display:none">&nbsp;</span></span>
</li>
<li id="cite_note-3"><span class="mw-cite-backlink"><a href="#cite_ref-3">↑</a></span> <span class="reference-text">W. Gellert, H. Küstner, M. Hellwich, H. Kästner: <i>Kleine Enzyklopädie Mathematik</i>; Leipzig 1970, S.&nbsp;433–434.</span>
</li>
<li id="cite_note-Bronstein-257-4"><span class="mw-cite-backlink">↑ <sup><a href="#cite_ref-Bronstein-257_4-0">a</a></sup> <sup><a href="#cite_ref-Bronstein-257_4-1">b</a></sup> <sup><a href="#cite_ref-Bronstein-257_4-2">c</a></sup></span> <span class="reference-text">Ilʹja N. Bronštejn: <cite style="font-style:italic">Taschenbuch der Mathematik</cite>. 11., aktualisierte Auflage. Haan-Gruiten 2020, ISBN 978-3-8085-5792-1, <span style="white-space:nowrap">S.<span style="display:inline-block;width:.2em">&nbsp;</span>257</span>.<span class="Z3988" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rfr_id=info:sid/de.wikipedia.org:Wendepunkt&amp;rft.au=Il%CA%B9ja+N.+Bron%C5%A1tejn&amp;rft.btitle=Taschenbuch+der+Mathematik&amp;rft.date=2020&amp;rft.edition=11.%2C+aktualisierte&amp;rft.genre=book&amp;rft.isbn=9783808557921&amp;rft.pages=257&amp;rft.place=Haan-Gruiten" style="display:none">&nbsp;</span></span>
</li>
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