I came across this proof in my notes and I could use some help getting started.

Let $\displaystyle n\in \mathbb{N}$. Then, prove that $\displaystyle x^n$ is differentiable at any point $\displaystyle x$ and $\displaystyle (x^n)'=nx^{n-1}$.

I know how to prove ones that are simpler such as $\displaystyle f(x)=x$ but this one is a bit harder for me to figure out.