.\" 386BSD man pages
.\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu)
.\" Modified 2002-08-10 by Walter Harms (walter.harms@informatik.uni-oldenburg.de)
-.TH COPYSIGN 3 2010-09-20 "GNU" "Linux Programmer's Manual"
+.TH COPYSIGN 3 2012-03-25 "GNU" "Linux Programmer's Manual"
.SH NAME
copysign, copysignf, copysignl \- copy sign of a number
.SH SYNOPSIS
.BR copysign ()
functions return a value whose absolute value matches
that of \fIx\fP, but whose sign bit matches that of \fIy\fP.
+
+For example,
+.I "copysign(42.0,\ \-1.0)"
+and
+.I "copysign(\-42.0, \-1.0)"
+both return \-42.0.
.SH RETURN VALUE
On success, these functions return a value whose magnitude is taken from
.I x