Question

What is the derivative of `f(x) = -5 e^{xcos x}`?

Answer 1

I found: `f'(x)=-5e^[xcos(x)]xx[cos(x)-xsin(x)]`

Explanation:

Here I would use the Chain Rule to deal first with `e` (red) and then with the exponent (blue where you need the Product Rule):
`f'(x)=-5color(red)(e^[xcos(x)])xxcolor(blue)([1*cos(x)-x*sin(x)])`