92 lines
2.8 KiB
Groff
92 lines
2.8 KiB
Groff
.\" Copyright (c) 1991 The 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: @(#)acos.3 5.1 (Berkeley) 5/2/91
|
|
.\" $FreeBSD: src/lib/msun/man/acos.3,v 1.13 2005/01/14 23:28:28 das Exp $
|
|
.\"
|
|
.Dd January 14, 2005
|
|
.Dt ACOS 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm acos ,
|
|
.Nm acosf
|
|
.Nd arc cosine functions
|
|
.Sh LIBRARY
|
|
.Lb libm
|
|
.Sh SYNOPSIS
|
|
.In math.h
|
|
.Ft double
|
|
.Fn acos "double x"
|
|
.Ft float
|
|
.Fn acosf "float x"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn acos
|
|
and the
|
|
.Fn acosf
|
|
functions compute the principal value of the arc cosine of
|
|
.Fa x .
|
|
A domain error occurs for arguments not in the range
|
|
.Bq -1 , +1 .
|
|
For a discussion of error due to roundoff, see
|
|
.Xr math 3 .
|
|
.Sh RETURN VALUES
|
|
The
|
|
.Fn acos
|
|
and the
|
|
.Fn acosf
|
|
functions return the arc cosine in the range
|
|
.Bq 0 , \*(Pi
|
|
radians.
|
|
If:
|
|
.Bd -unfilled -offset indent
|
|
.Pf \&| Ns Ar x Ns \&| > 1 ,
|
|
.Ed
|
|
.Pp
|
|
.Fn acos x
|
|
raises an invalid exception and returns an \*(Na.
|
|
.Sh SEE ALSO
|
|
.Xr asin 3 ,
|
|
.Xr atan 3 ,
|
|
.Xr atan2 3 ,
|
|
.Xr cos 3 ,
|
|
.Xr cosh 3 ,
|
|
.Xr fenv 3 ,
|
|
.Xr math 3 ,
|
|
.Xr sin 3 ,
|
|
.Xr sinh 3 ,
|
|
.Xr tan 3 ,
|
|
.Xr tanh 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn acos
|
|
function conforms to
|
|
.St -isoC .
|