Question

How do I find the derivative of `ln(5x)`?

Answer 1

You'll need the chain rule, which states that, when we cannot directly derivate the function, `(dy)/(dx)=(dy)/(du)(du)/(dx)`

Explanation:

Renaming `u=5x`, we can derivate `f(x)=ln(u)`, appyling the aforementioned rule.

`(dy)/(dx)=1/u*5`

`(dy)/(dx)=5/u=5/(5x)=1/x`