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

  \begin{exampleblock}{}
  Let $f(x) = e^x - x$. Find $f'$ and $f''$.
  \pause
  \begin{talign}
    f'(x) &= \mpause[1]{ e^x - 1 } & 
    \mpause[2]{f''(x) }&\mpause[2]{= }\mpause[3]{ e^x }
  \end{talign}\vspace{-2ex}
  \pause\pause\pause\pause
  \begin{center}
  \scalebox{.8}{
  \begin{tikzpicture}[default,baseline=1cm]
    \diagram{-3}{3}{-1}{3}{1}
    \diagramannotatez
    \diagramannotatex{-1,1}
    \diagramannotatey{-1,1}
    \begin{scope}[ultra thick]
      \draw[cgreen,ultra thick] plot[smooth,domain=-3:1.5,samples=30] function{exp(x) - x};
      \node[cgreen] at (-2.5,3) {$f$};
      \draw[cred,ultra thick] plot[smooth,domain=-3:1.4,samples=30] function{exp(x) - 1};
      \node[cred] at (-2.5,-.5) {$f'$};
    \end{scope}
  \end{tikzpicture}
  }
  \end{center} \smallskip   
  \end{exampleblock}
\end{frame}