COSH(3)			   Linux Programmer's Manual		       COSH(3)



NAME
       cosh, coshf, coshl - hyperbolic cosine function

SYNOPSIS
       #include <math.h>

       double cosh(double x);
       float coshf(float x);
       long double coshl(long double x);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       coshf(), coshl():
	   _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
	       || /* Since glibc 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       These  functions	 return	 the  hyperbolic cosine of x, which is defined
       mathematically as:

	   cosh(x) = (exp(x) + exp(-x)) / 2

RETURN VALUE
       On success, these functions return the hyperbolic cosine of x.

       If x is a NaN, a NaN is returned.

       If x is +0 or -0, 1 is returned.

       If x is positive infinity or negative infinity,	positive  infinity  is
       returned.

       If the result overflows, a range error occurs, and the functions return
       +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, respectively.

ERRORS
       See math_error(7) for information on how to determine whether an	 error
       has occurred when calling these functions.

       The following errors can occur:

       Range error: result overflow
	      errno  is	 set  to ERANGE.  An overflow floating-point exception
	      (FE_OVERFLOW) is raised.

ATTRIBUTES
       For  an	explanation  of	 the  terms  used   in	 this	section,   see
       attributes(7).

       +-------------------------+---------------+---------+
       |Interface		 | Attribute	 | Value   |
       +-------------------------+---------------+---------+
       |cosh(), coshf(), coshl() | Thread safety | MT-Safe |
       +-------------------------+---------------+---------+
CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD.

BUGS
       In   glibc  version  2.3.4  and	earlier,  an  overflow	floating-point
       (FE_OVERFLOW) exception is not raised when an overflow occurs.

SEE ALSO
       acosh(3), asinh(3), atanh(3), ccos(3), sinh(3), tanh(3)

COLOPHON
       This page is part of release 4.10 of the Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at
       https://www.kernel.org/doc/man-pages/.



				  2016-03-15			       COSH(3)