cosh (3) Linux Manual Page
cosh, coshf, coshl – hyperbolic cosine function
Synopsis
#include <math.h>Link with -lm.
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 versions <= 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 |
Conforming To
C99, POSIX.1-2001, POSIX.1-2008. The variant returning double also conforms to SVr4, 4.3BSD.