cos(3)                                                Library Functions Manual                                               cos(3)

NAME
       cos, cosf, cosl - cosine function

LIBRARY
       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 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 │
       └─────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS
       C99, POSIX.1-2001, POSIX.1-2008.

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

BUGS
       Before glibc 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)

Linux man-pages 6.03                                         2023-02-05                                                      cos(3)