cos

The cos function calculates the cosine of the floating-point value x. The value of x must be in the range ±2^32 (±4294967296.0). Outside this value range an NaN error is returned.

The cos function returns the cosine for the value x.

sin, tan

#include <math.h>
#include <stdio.h> /* for printf */

void tst_cos (void) {
  float x;
  float y;

  for (x = 0; x < (2 * 3.1415); x += 0.1) {
    y = cos (x);

    printf ("COS(%f) = %f\n", x, y);
  }
}