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+.\" 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
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+.\" SUCH DAMAGE.
+.\"
+.\"     from: @(#)ieee.3	6.4 (Berkeley) 5/6/91
+.\" $FreeBSD: src/lib/msun/man/copysign.3,v 1.1 2005/01/27 05:46:16 das Exp $
+.\"
+.Dd January 26, 2005
+.Dt COPYSIGN 3
+.Os
+.Sh NAME
+.Nm copysign ,
+.Nm copysignf ,
+.Nm copysignl
+.Nd copy sign
+.Sh LIBRARY
+.Lb libm
+.Sh SYNOPSIS
+.In math.h
+.Ft double
+.Fn copysign "double x" "double y"
+.Ft float
+.Fn copysignf "float x" "float y"
+.Ft long double
+.Fn copysignl "long double x" "long double y"
+.Sh DESCRIPTION
+The
+.Fn copysign ,
+.Fn copysignf
+and
+.Fn copysignl
+functions
+return
+.Fa x
+with its sign changed to
+.Fa y Ns 's .
+.Sh SEE ALSO
+.Xr fabs 3 ,
+.Xr fdim 3 ,
+.Xr ieee 3 ,
+.Xr math 3
+.Sh STANDARDS
+The
+.Fn copysign ,
+.Fn copysignf ,
+and
+.Fn copysignl
+routines conform to
+.St -isoC-99 .
+They implement the Copysign function recommended by
+.St -ieee754 .
+.Sh HISTORY
+The
+.Fn copysign ,
+.Fn copysignf ,
+and
+.Fn copysignl
+functions appeared in
+.Bx 4.3 ,
+.Fx 2.0 ,
+and
+.Fx 5.3 ,
+respectively.