we have $\displaystyle f,g : [a,b] \to \mathbb{R}$. If the statement is false provide counterexample and if true prove it. If $\displaystyle f = g^2$ and $\displaystyle f$ is differentiable on $\displaystyle [a,b]$, then $\displaystyle g$ is differentiable on $\displaystyle (a,b)$.

Please help a brother get started. (Nod)