.\" Copyright (c) 1991 The Regents of the University of California.
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.\"     from: @(#)cos.3	5.1 (Berkeley) 5/2/91
.\" $FreeBSD: src/lib/msun/man/cos.3,v 1.11 2001/10/13 12:23:23 bde Exp $
.\"
.Dd May 2, 1991
.Dt COS 3
.Os
.Sh NAME
.Nm cos ,
.Nm cosf
.Nd cosine functions
.Sh LIBRARY
.Lb libm
.Sh SYNOPSIS
.In math.h
.Ft double
.Fn cos "double x"
.Ft float
.Fn cosf "float x"
.Sh DESCRIPTION
The
.Fn cos
and the
.Fn cosf
functions compute the cosine of
.Fa x
(measured in radians).
A large magnitude argument may yield a result with little or no
significance.
For a discussion of error due to roundoff, see
.Xr math 3 .
.Sh RETURN VALUES
The
.Fn cos
and the
.Fn cosf
functions return the cosine value.
.Sh SEE ALSO
.Xr acos 3 ,
.Xr asin 3 ,
.Xr atan 3 ,
.Xr atan2 3 ,
.Xr cosh 3 ,
.Xr math 3 ,
.Xr sin 3 ,
.Xr sinh 3 ,
.Xr tan 3 ,
.Xr tanh 3
.Sh STANDARDS
The
.Fn cos
function conforms to
.St -isoC .