\section{COSH Hyperbolic Cosine Function}

\subsection{Usage}

Computes the hyperbolic cosine of the argument.
The syntax for its use is
\begin{verbatim}
   y = cosh(x)
\end{verbatim}
\subsection{Function Internals}

The \verb|cosh| function is computed from the formula
\[
   \cosh(x) = \frac{e^x+e^{-x}}{2}
\]
\subsection{Examples}

Here is a simple plot of the hyperbolic cosine function
\begin{verbatim}
--> x = linspace(-5,5);
--> plot(x,cosh(x)); grid('on');

\end{verbatim}


\centerline{\includegraphics[width=8cm]{coshplot}}

