Question

How do you differentiate `f(x) = xcos((pix)/2)` using the chain rule?

Answer 1

This problem actually requires BOTH the chain rule and the product rule ...

Explanation:

`f'(x)=cos((pix)/2)+x(-sin((pix)/2)xxpi/2)`

Now simplify, ...

`cos((pix)/2)-(pix)/2sin((pix)/2)`

Hope that helped