\begin{frame} \frametitle{Differentiation Rules: Chain Rule} \begin{block}{} \begin{malign} (f\circ g)'(x) \;=\; f'(g(x)) \cdot g'(x) \end{malign} \end{block} \begin{exampleblock}{} Use \begin{talign} \frac{d}{dx} e^x = e^x \end{talign} and the chain rule to prove \begin{talign} \frac{d}{dx} a^x = \ln a \cdot a^x \end{talign} \pause\medskip We have \begin{talign} a^x \;=\; \mpause[1]{(e^{\ln a})^x} \mpause[2]{ = e^{\ln a\cdot x}} \end{talign} \pause\pause\pause and $f = g\circ h$ where \;\;$g(x) = \mpause[1]{e^x}$\;\; and \;\;$h(x) = \mpause[2]{\ln a \cdot x}$\;\;. \pause\pause\pause Thus \begin{talign} f'(x) = g'(h(x)) \cdot h'(x) = \mpause[1]{ e^{\ln a \cdot x} \cdot \ln a} \mpause[2]{= \ln a \cdot a^x} \end{talign} \end{exampleblock} \vspace{10cm} \end{frame}