#include <stdio.h>
#include <math.h>

#define STEP  100
#define MAX_T 10

double v(double t){
  return cos(t);
}

int main(void) {
  
  double t = 0.0;
  double x = 0.0;
  double delta = 1.e-2;
  
  int i = 0;
  
  do {
    x += delta * v(t);
    t += delta;
    if( (i++) % STEP ==0 ){
      printf("%12.9f,%12.9f\n",t,x);
      i = 0;
    }
  } while ( t < MAX_T );
  
  return 0;
}