ACOSH
Section: Linux Programmer's Manual (3)
Updated: 20170915
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NAME
acosh, acoshf, acoshl  inverse hyperbolic cosine function
SYNOPSIS
#include <math.h>
double acosh(double x);
float acoshf(float x);
long double acoshl(long double x);
Link with lm.
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 versions <= 2.19: */ _BSD_SOURCE  _SVID_SOURCE
acoshf(),
acoshl():

_ISOC99_SOURCE  _POSIX_C_SOURCE >= 200112L
 /* Since glibc 2.19: */ _DEFAULT_SOURCE
 /* Glibc versions <= 2.19: */ _BSD_SOURCE  _SVID_SOURCE
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 floatingpoint 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  MTSafe

CONFORMING TO
C99, POSIX.12001, POSIX.12008.
The variant returning
double
also conforms to
SVr4, 4.3BSD.
SEE ALSO
asinh(3),
atanh(3),
cacosh(3),
cosh(3),
sinh(3),
tanh(3)
COLOPHON
This page is part of release 4.15 of the Linux
manpages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
https://www.kernel.org/doc/manpages/.
Index
 NAME

 SYNOPSIS

 DESCRIPTION

 RETURN VALUE

 ERRORS

 ATTRIBUTES

 CONFORMING TO

 SEE ALSO

 COLOPHON

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Time: 02:55:40 GMT, September 23, 2018