\begin{frame}
  \frametitle{Derivatives of Trigonometric Functions}
  
  \begin{exampleblock}{}
    Differentiate $f(x) = \sin(\cos(\tan x))$.
    \pause\medskip
    \begin{talign}
      f'(x) &= \mpause[1]{ \cos( \;\;\cos(\tan x)\;\; ) \cdot \frac{d}{dx} \cos(\tan x) }\\
      &\mpause[2]{= \cos(\cos(\tan x))  \cdot (-\sin (\tan x)) \cdot \frac{d}{dx} \tan x } \\
      &\mpause[3]{= -\cos(\cos(\tan x))  \cdot \sin (\tan x) \cdot \frac{1}{\cos^2 x} } 
    \end{talign}
    \pause\pause\pause\pause
    
    Note that we have applied the chain rule twice!
  \end{exampleblock}
\end{frame}