acoshf (3)
Leading comments
Copyright 1993 David Metcalfe (david@prism.demon.co.uk) and Copyright 2008, Linux Foundation, written by Michael Kerrisk <mtk.manpages@gmail.com> %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting ...
NAME
acosh, acoshf, acoshl - inverse hyperbolic cosine functionSYNOPSIS
#include <math.h> double acosh(double x);Link with -lm.
float acoshf(float x);
long double acoshl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
acosh():
-
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
acoshf(), acoshl():
-
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTION
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 |
CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.The variant returning double also conforms to SVr4, 4.3BSD, C89.