COS(3) Library Functions Manual COS(3)

cos, cosf
cosine function

Math Library (libm, -lm)

#include <math.h>

double
cos(double x);

float
cosf(float x);

The cos() and cosf() 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”).
May 2, 1991 NetBSD 8.99