Mise en forme d'une remarque

\begin{remark}
\begin{itemize}
\item[(1)] For all $n\in \N,$ $U_{n}$ is a polynomial of degree $n$  with coefficient in $\R$ therefore $U_{n}^{(n)} \in \R. $\\
\item[(2)] For all $n\in \N,$ $U_{n}$ $(U_{n}(\cos(\pi x)))^{'} = - \pi \sin(\pi x) U_{n}^{'}(\cos(\pi x)).$
\end{itemize}
\end{remark}