cosh(3) — Linux manual page


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

NAME         top

       cosh, coshf, coshl - hyperbolic cosine function

SYNOPSIS         top

       #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

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

DESCRIPTION         top

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

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

RETURN VALUE         top

       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         top

       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         top

       For an explanation of the terms used in this section, see

       │Interface                             Attribute     Value   │
       │cosh(), coshf(), coshl()              │ Thread safety │ MT-Safe │

CONFORMING TO         top

       C99, POSIX.1-2001, POSIX.1-2008.

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

BUGS         top

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

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 5.13 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

                               2021-03-22                        COSH(3)

Pages that refer to this page: acosh(3)asinh(3)atanh(3)sinh(3)tanh(3)