COS(3)			   Linux Programmer's Manual			COS(3)



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():
	   _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
	       || /* Since glibc 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       These functions return 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
	      errno  is set to EDOM (but see BUGS).  An invalid floating-point
	      exception (FE_INVALID) is raised.

ATTRIBUTES
       For  an	explanation  of	 the  terms  used   in	 this	section,   see
       attributes(7).

       +----------------------+---------------+---------+
       |Interface	      | Attribute     | Value	|
       +----------------------+---------------+---------+
       |cos(), cosf(), cosl() | Thread safety | MT-Safe |
       +----------------------+---------------+---------+
CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD.

BUGS
       Before version 2.10, the glibc implementation did not set errno to EDOM
       when a domain error occurred.

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 4.10 of the Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at
       https://www.kernel.org/doc/man-pages/.



				  2016-03-15				COS(3)