cosh(3)                    Library Functions Manual                    cosh(3)

NAME
       cosh, coshf, coshl - hyperbolic cosine function

LIBRARY
       Math library (libm, -lm)

SYNOPSIS
       #include <math.h>

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

   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 <= 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 |
       +--------------------------------------------+---------------+---------+
STANDARDS
       C11, POSIX.1-2008.

HISTORY
       C99, POSIX.1-2001.

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

BUGS
       In glibc 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)

Linux man-pages 6.7               2023-10-31                           cosh(3)