please help with this question..

First, it is given that f(x) is a differentiable function.

and

$\displaystyle

\frac{d}{dx}(f(x))^2 = 2 f(x) f '(x)

$

Then, I have to prove by MI that

$\displaystyle

\frac{d}{dx}(f(x))^n = n (f(x)) ^{n-1}f '(x)

$

I don' t understand how to prove it . please help~