Question

What is the derivative of `[lnx]^8`?

Answer 1

We'll need chain rule here.

Explanation:

• Chain rule states that `(dy)/(dx)=(dy)/(du)(du)/(dx)`

Renaming `u=lnx`, we get `f(x)=u^8`

`(df(x))/(dx)=8u^7(1/x)=(8(lnx)^7)/x`