cos, cosf, cosl - cosine function
Math library (
libm,
-lm)
#include <math.h>
double cos(double x);
float cosf(float x);
long double cosl(long double x);
cosf(),
cosl():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
These functions return the cosine of
x, where
x is given in
radians.
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.
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.
For an explanation of the terms used in this section, see
attributes(7).
Interface |
Attribute |
Value |
cos (), cosf (), cosl () |
Thread safety |
MT-Safe |
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double also conforms to SVr4, 4.3BSD.
Before glibc 2.10, the glibc implementation did not set
errno to
EDOM when a domain error occurred.
acos(3),
asin(3),
atan(3),
atan2(3),
ccos(3),
sin(3),
sincos(3),
tan(3)