Suppose that the function $\displaystyle f: \mathbb {R} \rightarrow \mathbb {R} $ is differentiable at $\displaystyle x_0 = 0$. Prove that $\displaystyle \lim _{x \rightarrow 0} \frac {f(x^2)-f(0)}{x} = 0 $

How should I approach the $\displaystyle f(x^2)$ here?