ATANH(3) Linux Programmers Manual ATANH(3)
NAME
atanh, atanhf, atanhl  inverse hyperbolic tangent function
SYNOPSIS
#include
double atanh(double x);
float atanhf(float x);
long double atanhl(long double x);
Link with lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
atanh(), atanhf(), atanhl(): _BSD_SOURCE  _SVID_SOURCE 
_XOPEN_SOURCE >= 500  _ISOC99_SOURCE; or cc std=c99
DESCRIPTION
The atanh() function calculates the inverse hyperbolic tangent of x;
that is the value whose hyperbolic tangent is x. If the absolute value
of x is greater than 1.0, atanh() returns notanumber (NaN) and errno
is set.
ERRORS
EDOM x is out of range.
CONFORMING TO
SVr4, POSIX.12001, 4.3BSD, C89. The float and long double variants
are C99 requirements.
SEE ALSO
acosh(3), asinh(3), catanh(3), cosh(3), sinh(3), tanh(3)
COLOPHON
This page is part of release 3.05 of the Linux manpages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/manpages/.
20070726 ATANH(3)
