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():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
           _POSIX_C_SOURCE >= 200112L;
           or cc -std=c99

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 4.04 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 http://www.kernel.org/doc/man-pages/.

                                            2015-04-19                                    COSH(3)