\section{sinh --- Hyperbolic Sine}
\label{fn:sinh}
\index{sinh()}
\index{hyperbolic sine}
\index{sine!hyperbolic}
\begin{rail}
Sinh : 'sinh' '(' ( Scalar | Matrix ) ')' ;
\end{rail}

\verb+sinh+ calculates the hyperbolic sine of the argument, specified
in radians.  If the argument is a matrix, then the operation is 
performed element-by-element.

$\Longrightarrow$ This is not an \RLaB\ built-in function.  This function
is normally loaded on start-up from the \verb+sinh.r+ file in the
standard \verb+rlib+ directory. Use of the \verb+-r+ option, incorrectly 
setting the \verb+RLAB_LIB_DIR+ environmental variable, or modifying
\verb+sinh.r+ may make this function unavailable.


\paragraph{Example}
\index{example of sinh()}
\index{sinh()!example}
\begin{verbatim}
> sinh(0)
        0
> sinh(pi/2)
      2.3
> sinh(pi)
     11.5
> b = rand(2,5)*4
 b =
    0.367       3.84       1.76        3.7       3.63
     3.61       3.66      0.294      0.353       1.45
> sinh(b)
    0.376       23.2       2.83       20.2       18.9
     18.5       19.4      0.298       0.36       2.01 
\end{verbatim}

See also: Page~\pageref{fn:acosh} \verb+acosh()+,
Page~\pageref{fn:asinh} \verb+asinh()+,
Page~\pageref{fn:atanh} \verb+atanh()+,
Page~\pageref{fn:cosh} \verb+cosh()+,
Page~\pageref{fn:exp} \verb+exp()+,
Page~\pageref{fn:sin} \verb+sin()+,
Page~\pageref{fn:tanh} \verb+tanh()+.

\newpage



