1. ## Derivative of ln(-x)

Can someone please explain to me why the derivative of ln(-x) is 1/x?

Thanks!

2. ## Re: Derivative of ln(-x)

Originally Posted by otownsend
Can someone please explain to me why the derivative of ln(-x) is 1/x?

Thanks!
For $x<0$, $\frac d {dx} \ln(-x) = \frac 1 {-x} \frac d {dx} (-x) = \frac 1 {-x}(-1) = \frac 1 x$.