# Math Help - Trig Derivative

1. ## Trig Derivative

Anyone know what the derivative of cos(sinx) is?

Thanks.

2. Originally Posted by ctran
Anyone know what the derivative of cos(sinx) is?

Thanks.
Use the chain rule:

$\frac{d}{dx} f(g(x))=f'(g(x))g'(x)$

with $g(x)=\sin(x)$ and $f(x)=\cos(x)$

CB

3. Originally Posted by ctran
Anyone know what the derivative of cos(sinx) is?

Thanks.
let $y=cos(sinx)$

$\frac{dy}{dx}=-sin(sinx).cosx$

4. I'm sure glad you guys got in before me. I would have answered, "Yes!"