cos

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  at-
       tributes(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 5.05 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/.

                                  2017-09-15                            COS(3)