cosh(3) Linux Man Page - System Grab Bag

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). allbox; lbx lb lb T{ cosh()coshf()coshl()

Interface	Attribute	Value
T}	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.