Question

How do you find the derivative of `f(x) = -15 / (4x + 5)^4` using the chain rule?

Answer 1

I prefer to rewrite the function as `f(x) = -15(4x+5)^-4`

Explanation:

Then `f'(x) = 60(4x+5)^-5 d/dx(4x+5)`

`= 60(4x+5)^-5(4)`

`= 240/(4x+5)^5`