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

int main () {
   int i, n = 11, nm;
   float pi, f1, f2, x1, x2, xint;
   
	printf("  i        x       f(x)    int(f(x)) \n  1      0.00      1.00      0.00  \n");
	pi = acos(-1.0);
	nm = n-1;
	xint = 0.0;
	x1 = 0.0;
	for (i = 2; i <= n; i++) {
		x2 = ((i-1)/nm)*pi;
		f1 = cos(x1);
		f2 = cos(x2);
		xint = xint + 0.5*(f1+f2)*(x2-x1);
		x1 = x2;
		printf(" %d  %f  %f  %f \n ",i, x2, f2, xint);
	}
}