\begin{frame} \frametitle{Linear Approximation and Differentials} \begin{exampleblock}{Final Exam 2003 (Spring)} Use differentials or the linearization approximation method to approximate $\ln(0.9)$. \pause\bigskip We have $f(x) = \ln x$.\pause\bigskip We need to choose where to compute the linearization: $a = \pause 1$.\pause \begin{talign} f(1) &= \mpause[1]{0} \\ \mpause[2]{f'(x) }&\mpause[2]{= }\mpause[3]{\frac{1}{x}} & \mpause[4]{f'(1) = 1} \end{talign} \pause\pause\pause\pause\pause The linearization of $f$ at $1$ is:\vspace{-.7ex} \begin{talign} L(x) = \mpause[1]{0 + 1(x-1)} \mpause[2]{= x-1} \end{talign} \pause\pause\pause Then the approximation of $\ln(0.9)$ is:\vspace{-.7ex} \begin{talign} \ln(0.9) \approx \mpause[1]{L(0.9)} &\mpause[2]{= 0.9 - 1} \mpause[3]{= -0.1} \end{talign} \end{exampleblock} \end{frame}