huschi.net

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():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
           or cc -std=c99
DESCRIPTION
       The cosh() function returns  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.
CONFORMING TO
       C99, POSIX.1-2001.  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 3.53 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

                                  2010-09-20                           COSH(3)