Question

How do you differentiate `f(x) = -15 / (4x + 5)^4`?

Answer 1

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

Explanation:

As `f(x)=-15/(4x+5)^4=-15*(4x+5)^(-4)`

We can do a chain differentiation
`f'(x)=-15*((4x+5)^(-4))'*(4x)'`

`=-15*-4(4x+5)^(-5)*4`

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