Let $\displaystyle f$ be an integrable function on $\displaystyle \mathbb{R}$ with $\displaystyle f(0) = 0$. If $\displaystyle f$ is differentiable at $\displaystyle 0$, prove that the function $\displaystyle \frac{f(x)}{x}$ is integrable on $\displaystyle \mathbb{R}$.

How do I go about doing it? Thanks in advance.