I removed slides that worked, checked that they compiled properly and include here all the slides that didn't work (checked individually as well).
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\begin{document}
\sffamily \bfseries
\begin{frame}
\frametitle{Limit of a Rational Polynomial Function}\pause
begin{itemize}
\item Let us find $\lim_{x \to \2} \frac {3x^{2}-x-10} {x^{2}-4}$
\end{itemize}
\end{frame}
\begin{frame}
\frametitle{Limit of a Rational Polynomial Function}\pause
begin{itemize}
\item To understand limits of functions
\end{itemize}
$\lim_{x \to \2} \frac {3x^{2}-x-10} {x^{2}-4} = 2.75$
\end{frame}
\begin{frame}
\frametitle{Limit of a Discontinuous Function}\pause
Let us find $\lim_{x \to \0} f(x) = \[ \left\{
\begin{array}{11}
$(2x+3) & x \leq 0$ \\
$3(x+1) & x $>$ 0$ \\
\end{array}
\right. \]
and $\lim_{x \to \1} f(x) = \[ \left\{
\begin{array}{11}
$(2x+3) & x \leq 0$ \\
$3(x+1) & x $>$ 0$ \\
\end{array}
\right. \]
\end{frame}
\begin{frame}
\frametitle{Limit of a Discontinuous Function}\pause
Let us find $\lim_{x \to \0} f(x) = \[ \left\{
\begin{array}{11}
$(2x+3) & x \leq 0$ = 3 \\
$3(x+1) & x $>$ 0$ \\
\end{array}
\right. \]
and $\lim_{x \to \1} f(x) = \[ \left\{
\begin{array}{11}
$(2x+3) & x \leq 0$ = 6 \\
$3(x+1) & x $>$ 0$ \\
\end{array}
\right. \]
\end{frame}
\begin{frame}
\frametitle{Assignment}\pause
\begin{itemize} [<+-|alert@+>]
\item Find $\lim_{x \to \2} (x^{3}-2x^{2})/(x^{2}-5x+6)$
\item Evaluate $\lim_{x \to \0} \frac {sin 4x} {sin 2x}$
\end{itemize}
\end{frame}
\end{document}
$inside te array. Conversely the 11th slide is missing a$to end the mathematics – David Carlisle Apr 25 '18 at 15:48$in the item of the 11th slide. And aren't the line breaks in the arrays after the last entry superfluous? – naphaneal Apr 25 '18 at 15:53begin{itemize}. Is that really\begin{itemize}? – Teepeemm Apr 25 '18 at 15:56