\begin{frame}
  \frametitle{Derivatives of Trigonometric Functions}

  We have the following identities for $\sin$ and $\cos$:
  \smallskip
  
  \begin{block}{}
    \begin{malign}
      \sin(x+y) \;&=\; \sin x \cdot \cos y + \cos x \cdot \sin y\\
      \cos(x+y) \;&=\; \cos x \cdot \cos y - \sin x \cdot \sin y
    \end{malign}
  \end{block}
\end{frame}