# cosh(3) [linux man page]

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

cosh, coshf, coshl - hyperbolic cosine functionSYNOPSIS

#include <math.h> double cosh(double x); float coshf(float x); long double coshl(long double x); Link withFeature 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-lm.-std=c99DESCRIPTION

The cosh() function returns the hyperbolic cosine of x, which is defined mathematically as: cosh(x) = (exp(x) + exp(-x)) / 2RETURN 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, 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.-0ERRORS

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 3.27 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)

## Check Out this Related Man Page

cosh(3M) Mathematical Library Functions cosh(3M)NAME

cosh, coshf, coshl - hyperbolic cosine functionSYNOPSIS

c99 [ flag... ] file...[ library... ] #include <math.h> double cosh(double x); float coshf(float x); long double coshl(long double x);-lmDESCRIPTION

These functions compute the hyperbolic cosine of their argument x.RETURN VALUES

Upon successful completion, these functions return the hyperbolic cosine of x. If the correct value would cause overflow, a range error occurs and cosh(), coshf(), and coshl() return the value of the macro HUGE_VAL, HUGE_VALF, and HUGE_VALL, respectively. If x is NaN, a NaN is returned. If x is +-0, 1.0 is returned. If x is +-Inf, +-Inf is returned. For exceptional cases, matherr(3M) tabulates the values to be returned by cosh() as specified by SVID3 and XPG3.ERRORS

These functions will fail if: Range Error The result would cause an overflow. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the overflow floating-point exception is raised. The cosh() function sets errno to ERANGE if the result would cause an overflow.USAGE

An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions. An application can also set errno to 0 before calling cosh(). On return, if errno is non-zero, an error has occurred. The coshf() and coshl() functions do not set errno.ATTRIBUTES

See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+SEE ALSO

acosh(3M), feclearexcept(3M), fetestexcept(3M), isnan(3M), math.h(3HEAD), matherr(3M), sinh(3M), tanh(3M), attributes(5), standards(5)SunOS 5.1112 Jul 2006 cosh(3M)