题目
13.设f(x)具有一阶连续导数,且y=e^f(2sinx),求y'.
13.设f(x)具有一阶连续导数,且$y=e^{f(2sinx)}$,求y'.
题目解答
答案
设 $ u = f(2\sin x) $,则 $ y = e^u $。应用链式法则:
1. 求 $ \frac{dy}{du} $:
\[
\frac{dy}{du} = e^u = e^{f(2\sin x)}
\]
2. 求 $ \frac{du}{dx} $:
设 $ v = 2\sin x $,则 $ u = f(v) $,
\[
\frac{du}{dx} = f'(v) \cdot \frac{dv}{dx} = f'(2\sin x) \cdot 2\cos x
\]
3. 综合求导:
\[
y' = \frac{dy}{du} \cdot \frac{du}{dx} = e^{f(2\sin x)} \cdot f'(2\sin x) \cdot 2\cos x
\]
答案:
\[
\boxed{2e^{f(2\sin x)} f'(2\sin x) \cos x}
\]