\begin{frame} \frametitle{Derivatives of Basic Functions} \begin{block}{} The \emph{normal line} is perpendicular to the tangent.\pause\medskip If the tangent has slope $m$, then the normal line has slope $-\frac{1}{m}$. \end{block} \pause \begin{exampleblock}{} Find equations for the tangent and normal line to $x\sqrt{x}$ at $(1,1)$. \pause \begin{talign} f'(x) = \frac{d}{dx}(x\sqrt{x}) \mpause[1]{ = \frac{d}{dx}(x^{1.5})} \mpause[2]{= 1.5 x^{.5}} \mpause[3]{= \frac{3}{2} \sqrt{x}} \end{talign} \pause\pause\pause\pause The slope of the tangent at $(1,1)$ is $\frac{3}{2}$. \pause Hence the tangent is \begin{talign} y - 1= \frac{3}{2} (x-1) && y = \frac{3}{2} x - \frac{1}{2} \end{talign} \pause The slope of the normal at $(1,1)$ is $-1/\frac{3}{2} = -\frac{2}{3}$. \pause Hence the normal is \begin{talign} y - 1= -\frac{2}{3} (x-1) && y = -\frac{2}{3} x + \frac{5}{3} \end{talign} \end{exampleblock} \end{frame}