COS(3) Library Functions Manual COS(3)

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);

The cos(), cosf(), and cosl() functions compute the cosine of x (measured in radians). A large magnitude argument may yield a result with little or no significance. For a discussion of error due to roundoff, see math(3).

The cos() function returns the cosine value.

acos(3), asin(3), atan(3), atan2(3), cosh(3), math(3), sin(3), sinh(3), tan(3), tanh(3)

The cos() function conforms to ANSI X3.159-1989 (“ANSI C89”).

A cos() function appeared in Version 1 AT&T UNIX.
September 2, 2019 NetBSD 9.0