\begin{frame} \frametitle{Limit: Continued} \begin{block}{} $\lim_{x\to a} f(x) = L$ if we can make the values of $f(x)$ arbitrarily close to $L$ by taking $x$ sufficiently close to $a$ but not equal to $a$. \end{block} \medskip \pause Note that we never consider $f(x)$ for $x=a$. \alert{The value of $f(a)$ does not matter.} In fact, $f(x)$ need not be defined for $x=a$. \bigskip \pause \begin{indentation}{-.35cm}{-.5cm} \begin{minipage}{.35\textwidth} \begin{center} \scalebox{.5}{ \begin{tikzpicture}[default,nodes={scale=1.4}] \diagram{-1}{5}{-1}{5}{1} \draw[cblue,ultra thick] plot[smooth,domain=-.8:4.5,samples=20] function{.2*x**3 - 1.0*(x+1)**2 + 3.4*x +2}; \def\x{3.5} \def\y{{.2*\x^3 - 1.0*(\x+1)^2 + 3.4*\x +2}} \begin{scope}[dashed,cred,ultra thick,inner sep=1mm] \draw (\x,\y) -- (\x,-2mm) node [below] {a}; \draw (\x,\y) -- (-2mm,\y) node [left] {$L$}; \end{scope} \end{tikzpicture} } $f(a) = L$ \end{center} \end{minipage} % \begin{minipage}{.35\textwidth} \begin{center} \scalebox{.5}{ \begin{tikzpicture}[default,nodes={scale=1.4}] \diagram{-1}{5}{-1}{5}{1} \draw[cblue,ultra thick] plot[smooth,domain=-.8:4.5,samples=20] function{.2*x**3 - 1.0*(x+1)**2 + 3.4*x +2}; \def\x{3.5} \def\y{{.2*\x^3 - 1.0*(\x+1)^2 + 3.4*\x +2}} \begin{scope}[dashed,cred,ultra thick,inner sep=1mm] \draw (\x,\y) -- (\x,-2mm) node [below] {a}; \draw (\x,\y) -- (-2mm,\y) node [left] {$L$}; \end{scope} \node[exclude={cblue}] at (\x,\y) {}; \node[include={cblue},yshift=-10mm] at (\x,\y) {}; \end{tikzpicture} } $f(a) \ne L$ \end{center} \end{minipage} % \begin{minipage}{.35\textwidth} \begin{center} \scalebox{.5}{ \begin{tikzpicture}[default,nodes={scale=1.4}] \diagram{-1}{5}{-1}{5}{1} \draw[cblue,ultra thick] plot[smooth,domain=-.8:4.5,samples=20] function{.2*x**3 - 1.0*(x+1)**2 + 3.4*x +2}; \def\x{3.5} \def\y{{.2*\x^3 - 1.0*(\x+1)^2 + 3.4*\x +2}} \begin{scope}[dashed,cred,ultra thick,inner sep=1mm] \draw (\x,\y) -- (\x,-2mm) node [below] {a}; \draw (\x,\y) -- (-2mm,\y) node [left] {$L$}; \end{scope} \node[exclude={cblue}] at (\x,\y) {}; \end{tikzpicture} } $f(a)$ undefined \end{center} \end{minipage} \end{indentation} \pause\medskip \begin{exampleblock}{} In each of these cases we have $\lim_{x\to a} f(x) = L$! \end{exampleblock} \vspace{10cm} \end{frame}