\" Copyright (c) 1985, 1991 Regents of the University of California.
\" All rights reserved.
\"
\" Redistribution and use in source and binary forms, with or without
\" modification, are permitted provided that the following conditions
\" are met:
\" 1. Redistributions of source code must retain the above copyright
\" notice, this list of conditions and the following disclaimer.
\" 2. Redistributions in binary form must reproduce the above copyright
\" notice, this list of conditions and the following disclaimer in the
\" documentation and/or other materials provided with the distribution.
\" 3. Neither the name of the University nor the names of its contributors
\" may be used to endorse or promote products derived from this software
\" without specific prior written permission.
\"
\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
\" SUCH DAMAGE.
\"
\" from: @(#)atanh.3 5.2 (Berkeley) 5/6/91
\" $NetBSD: atanh.3,v 1.18 2022/12/04 11:25:09 uwe Exp $
\"
Dd January 29, 2013
Dt ATANH 3
Os
Sh NAME
Nm atanh ,
Nm atanhf ,
Nm atanhl
Nd inverse hyperbolic tangent function
Sh LIBRARY
Lb libm
Sh SYNOPSIS
In math.h
Ft double
Fn atanh "double x"
Ft float
Fn atanhf "float x"
Ft long double
Fn atanhl "long double x"
Sh DESCRIPTION
The
Fn atanh ,
Fn atanhf ,
and
Fn atanhl
functions compute the inverse hyperbolic tangent
of the real
argument
Ar x .
Sh RETURN VALUES
If |x|\*[Ge]1,
Fn atanh "x" ,
Fn atanhf "x" ,
and
Fn atanhl "x"
\" POSIX_MODE
return +inf, -inf or NaN, and sets the global variable
Va errno
to
Er EDOM .
\" SYSV_MODE
\" call
\" .Xr matherr 3 .
Sh SEE ALSO
Xr acosh 3 ,
Xr asinh 3 ,
Xr exp 3 ,
Xr math 3
\" .Xr matherr 3
Sh STANDARDS
The
Fn atanh
function conforms to
St -isoC-99 .
Sh HISTORY
The
Fn atanh
function appeared in
Bx 4.3 .
