Name
cos, cosf, cosl - cosine functionLibrary
Math library ( libm ", " -lm )Synopsis
#include <math.h> double cos(double x );
float cosf(float x );
long double cosl(long double x );
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 <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
Description
These functions return the cosine ofx
, where x is given in radians. Return Value
On success, these functions return the cosine ofx
. 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 |
T} | Thread safety | MT-Safe |
Standards
C11, POSIX.1-2008.History
C89, POSIX.1-2001.The variant returning double also conforms to SVr4, 4.3BSD.