If $f$ is an analytical function in $C$ and $f(R) \subseteq R$ prove that $f^{(n)}(R) \subseteq R$, for all $n ∈ N$
Prove that $f$ analytic, $f(x) \in \mathbb{R}$ for all $x \in \mathbb{R}$ implies $f(\overline{z})=\overline{f(z)}$