/* @(#)z_cosh.c 1.0 98/08/13 *//*FUNCTION        <<cosh>>, <<coshf>>---hyperbolic cosineANSI_SYNOPSIS        #include <math.h>        double cosh(double <[x]>);        float coshf(float <[x]>)TRAD_SYNOPSIS        #include <math.h>        double cosh(<[x]>)        double <[x]>;        float coshf(<[x]>)        float <[x]>;DESCRIPTION        <<cosh>> computes the hyperbolic cosine of the argument <[x]>.        <<cosh(<[x]>)>> is defined as        @ifnottex        . (exp(x) + exp(-x))/2        @end ifnottex        @tex        $${(e^x + e^{-x})} \over 2$$        @end tex        Angles are specified in radians.        <<coshf>> is identical, save that it takes and returns <<float>>.RETURNS        The computed value is returned.  When the correct value would create        an overflow,  <<cosh>> returns the value <<HUGE_VAL>> with the        appropriate sign, and the global value <<errno>> is set to <<ERANGE>>.        You can modify error handling for these functions using the        function <<matherr>>.PORTABILITY        <<cosh>> is ANSI.        <<coshf>> is an extension.QUICKREF        cosh ansi pure        coshf - pure*//****************************************************************** * Hyperbolic Cosine * * Input: *   x - floating point value * * Output: *   hyperbolic cosine of x * * Description: *   This routine returns the hyperbolic cosine of x. * *****************************************************************/#include "fdlibm.h"#include "zmath.h"#ifndef _DOUBLE_IS_32BITSdouble_DEFUN (cosh, (double),        double x){  return (sineh (x, 1));}#endif /* _DOUBLE_IS_32BITS */