#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);
   }
}

void tst_sin (void) {
  float x;
  float y;
  for(x =0;x <(2 *3.1415); x += 0.1) {
    y = sin (x);
    printf ("SIN(%f) = %f\n", x, y);
  }
}

void tst_tan (void) {
  float x, y, pi;
  pi = 3.14159;
  for (x = -(pi/4); x < (pi/4); x += 0.1) {
    y = tan (x);
    printf ("TAN(%f) = %f\n", x, y);
  }
}