Question

What is the derivative of `f(x)=cos(pi*x^2)`?

Answer 1

`-2pixsin(pix^2)`

Explanation:

From standard rules of differentiation, the derivative of the cosine of a function is the negative sine of the function multiplied by the derivative of the function.

Applying this rule yields :

`d/dxcos(pix^2)=-sin(pix^2)*d/dxpix^2`

`=-sin(pix^2)*2pix`