Question

How do you find the derivative of `y=(ln x)^3`?

Answer 1

Simple chain rule use here.

Be `u=lnx`, then we apply chain rule as follows

`(dy)/(du)*(du)/(dx)=(dy)/(dx)`

`(dy)/(dx)=3u^2*du=3(lnx)^2*1/x`

`(dy)/(dx)=(3(lnx)^2)/x`