Lösung 1.2:2f
Aus Online Mathematik Brückenkurs 2
K (Lösning 1.2:2f moved to Solution 1.2:2f: Robot: moved page) |
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- | {{ | + | The entire expression is made up of several levels, |
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- | {{ | + | <math>\cos \left\{ \left. \sqrt{\left\{ \left. 1-x \right\} \right.} \right\} \right.</math> |
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+ | and when we differentiate we go from the outside inwards. In the first stage, we consider the expression as "cos of something", | ||
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+ | <math>\cos \left\{ \left. {} \right\} \right.</math> | ||
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+ | and differentiate this using the chain rule: | ||
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+ | <math>\frac{d}{dx}\cos \left\{ \left. \sqrt{1-x} \right\} \right.=-\sin \left\{ \left. \sqrt{1-x} \right\} \right.\centerdot \left( \left\{ \left. \sqrt{1-x} \right\} \right. \right)^{\prime }</math> | ||
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+ | In the next differentiation, we have "the root of something", | ||
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+ | <math>\left( \sqrt{\left\{ \left. 1-x \right\} \right.} \right)^{\prime }=\frac{1}{2\sqrt{1-x}}\centerdot \left( 1-x \right)^{\prime }</math> | ||
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+ | where we have used the differentiation rule, | ||
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+ | <math>\frac{d}{dx}\left( \sqrt{x} \right)=\frac{1}{2\sqrt{x}}</math> | ||
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+ | for the outer derivative. | ||
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+ | The whole differentiation in one go becomes: | ||
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+ | <math>\begin{align} | ||
+ | & \frac{d}{dx}\cos \sqrt{1-x}=-\sin \sqrt{1-x}\centerdot \frac{d}{dx}\sqrt{1-x} \\ | ||
+ | & =-\sin \sqrt{1-x}\centerdot \frac{1}{2\sqrt{1-x}}\centerdot \frac{d}{dx}\left( 1-x \right) \\ | ||
+ | & =-\sin \sqrt{1-x}\centerdot \frac{1}{2\sqrt{1-x}}\centerdot \left( -1 \right) \\ | ||
+ | & =\frac{\sin \sqrt{1-x}}{2\sqrt{1-x}} \\ | ||
+ | \end{align}</math> |
Version vom 13:53, 11. Okt. 2008
The entire expression is made up of several levels,
\displaystyle \cos \left\{ \left. \sqrt{\left\{ \left. 1-x \right\} \right.} \right\} \right.
and when we differentiate we go from the outside inwards. In the first stage, we consider the expression as "cos of something",
\displaystyle \cos \left\{ \left. {} \right\} \right.
and differentiate this using the chain rule:
\displaystyle \frac{d}{dx}\cos \left\{ \left. \sqrt{1-x} \right\} \right.=-\sin \left\{ \left. \sqrt{1-x} \right\} \right.\centerdot \left( \left\{ \left. \sqrt{1-x} \right\} \right. \right)^{\prime }
In the next differentiation, we have "the root of something",
\displaystyle \left( \sqrt{\left\{ \left. 1-x \right\} \right.} \right)^{\prime }=\frac{1}{2\sqrt{1-x}}\centerdot \left( 1-x \right)^{\prime }
where we have used the differentiation rule,
\displaystyle \frac{d}{dx}\left( \sqrt{x} \right)=\frac{1}{2\sqrt{x}}
for the outer derivative.
The whole differentiation in one go becomes:
\displaystyle \begin{align}
& \frac{d}{dx}\cos \sqrt{1-x}=-\sin \sqrt{1-x}\centerdot \frac{d}{dx}\sqrt{1-x} \\
& =-\sin \sqrt{1-x}\centerdot \frac{1}{2\sqrt{1-x}}\centerdot \frac{d}{dx}\left( 1-x \right) \\
& =-\sin \sqrt{1-x}\centerdot \frac{1}{2\sqrt{1-x}}\centerdot \left( -1 \right) \\
& =\frac{\sin \sqrt{1-x}}{2\sqrt{1-x}} \\
\end{align}