COS
Section: Linux Programmer's Manual (3)
Updated: 2009-02-04
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NAME
cos, cosf, cosl - cosine function
SYNOPSIS
#include <math.h>
double cos(double x);
float cosf(float x);
long double cosl(long double x);
Link with -lm.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
cosf(),
cosl():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or
cc -std=c99
DESCRIPTION
The
cos()
function returns the cosine of x, where x is
given in radians.
RETURN VALUE
On success, these functions return the cosine of
x.
If
x
is a NaN, a NaN is returned.
If
x
is positive infinity or negative infinity,
a domain error occurs,
and a NaN is returned.
ERRORS
See
math_error(7)
for information on how to determine whether an error has occurred
when calling these functions.
The following errors can occur:
- Domain error: x is an infinity
-
An invalid floating-point exception
(FE_INVALID)
is raised.
These functions do not set
errno.
CONFORMING TO
C99, POSIX.1-2001.
The variant returning
double
also conforms to
SVr4, 4.3BSD.
SEE ALSO
acos(3),
asin(3),
atan(3),
atan2(3),
ccos(3),
sin(3),
sincos(3),
tan(3)
COLOPHON
This page is part of release 3.22 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.