\begin{frame}
  \frametitle{L'Hospital's Rule}

  \begin{block}{}
    A limit of the form
    \begin{talign}
      \lim_{x \to a} (f(x) - g(x)) 
    \end{talign}
    where 
    \begin{talign}
      \lim_{x \to a} f(x) = \infty &&\text{and}&& \lim_{x \to a} g(x) = \infty
    \end{talign} 
    is called \emph{indeterminate form of type $\infty - \infty$}.
  \end{block}
  \pause\medskip

  We then rewrite the limit as a \emph{quotient}.
\end{frame}