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 4.09 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)





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