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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 4.09 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)



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