acoshf3
Inverse hyperbolic cosine function
Part of acosh(3).
Usage
#include <math.h>
double acosh(double x); float acoshf(float x); long double acoshl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
acosh():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| _XOPEN_SOURCE >= 500
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
acoshf(), acoshl():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
Library
Math library (libm, -lm)
Overview
These functions calculate the inverse hyperbolic cosine of x; that is the value whose hyperbolic cosine is x.
Return value
On success, these functions return the inverse hyperbolic cosine of x.
If x is a NaN, a NaN is returned.
If x is +1, +0 is returned.
If x is positive infinity, positive infinity is returned.
If x is less than 1, a domain error occurs, and the functions return a NaN.
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:
- Domain error: x is less than 1
-
errno is set to EDOM. An invalid floating-point exception (
FE_INVALID) is raised.
Attributes
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| acosh(), acoshf(), acoshl() | Thread safety | MT-Safe |
Releases
12 releases since Debian 3.1 (Sarge); the text changed 11 times.