#include <math.h>
#include <stdio.h>                 /* for printf */
void tst_exp (void) {
   float x;
   float y;
   x = 4.605170186;
   y = exp (x); /* y = 100 */
   printf ("EXP(%f) = %f\n", x, y);
}

void tst_log (void) {
  float x;
  float y;
  x = 2.71838;
  x *=x;
  y = log (x); /*y =2 */
  printf ("LOG(%f) = %f\n", x, y);
}

void tst_log10 (void) {
  float x;
  float y;
  x = 1000;
  y = log10 (x); /*y =3 */
  printf ("LOG10(%f) = %f\n", x, y);
}