86 lines
2.7 KiB
Groff
86 lines
2.7 KiB
Groff
.\" 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. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. 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
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd January 14, 2005
|
|
.Dt ATANH 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm atanh ,
|
|
.Nm atanhf
|
|
.Nd inverse hyperbolic tangent functions
|
|
.Sh LIBRARY
|
|
.Lb libm
|
|
.Sh SYNOPSIS
|
|
.In math.h
|
|
.Ft double
|
|
.Fn atanh "double x"
|
|
.Ft float
|
|
.Fn atanhf "float x"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn atanh
|
|
and the
|
|
.Fn atanhf
|
|
functions compute the inverse hyperbolic tangent
|
|
of the real
|
|
argument
|
|
.Ar x .
|
|
For a discussion of error due to roundoff, see
|
|
.Xr math 3 .
|
|
.Sh RETURN VALUES
|
|
The
|
|
.Fn atanh
|
|
and the
|
|
.Fn atanhf
|
|
functions
|
|
return the inverse hyperbolic tangent of
|
|
.Ar x
|
|
if successful.
|
|
If the argument has absolute value 1, a divide-by-zero exception
|
|
is raised and an infinity is returned.
|
|
If
|
|
.Ar |x|
|
|
> 1, an invalid exception is raised and an \*(Na is returned.
|
|
.Sh SEE ALSO
|
|
.Xr acosh 3 ,
|
|
.Xr asinh 3 ,
|
|
.Xr exp 3 ,
|
|
.Xr fenv 3 ,
|
|
.Xr math 3
|
|
.Sh HISTORY
|
|
The
|
|
.Fn atanh
|
|
function appeared in
|
|
.Bx 4.3 .
|