\begin{frame}
  \frametitle{The Substitution Rule: Exercises}

  \begin{exampleblock}{}
    Evaluate
    \begin{talign}
      \int x^2 e^{x^3}\, dx 
    \end{talign}
    \pause
    We take $u = \pause x^3$\pause, then $u' = \pause 3x^2$ \pause and
    \begin{talign}
      \int x^2 e^{x^3}\, dx 
      \mpause[1]{ &= \int x^2 e^{u} \, \frac{du}{3x^2} } \\
      \mpause{ &= \frac{1}{3} \int e^u \, du } \\
      \mpause{ &= \frac{1}{3}e^u + C }\\
      \mpause{ &= \frac{1}{3}e^{x^3} + C }
    \end{talign}
    \pause\pause\pause
  \end{exampleblock}
\end{frame}