cos, cosf, cosl - Cosine

Definition	#include <math.h> double cos(double x); float cosf(float x); (C11) long double cosl(long double x); (C11) These functions calculate the trigonometric function cosine for the floating-point number x.
Return val.	cos(x)      a floating-point number in the interval [-1.0, +1.0].
Example	The following program lists the cosine values corresponding to input values in the interval [-pi, +pi]. #include <math.h> #include <stdio.h> #define pi 3.14159265358979 int main(void) { double x; for (x = -pi; x <= pi; x = x + pi/4.) printf("cos(%f) = %f\n", x, cos(x)); return 0; }
See also	acos, cosh, sin, asin, sinh, tan, atan, atan2, tanh