Лабораторное задание №2.1

#include <iostream>
#include <math.h>

using namespace std;
const double pi = 3.1415926;

int main()
{
unsigned long i, n = 4;
double a,b,x,h,S1,S2,eps,exact;
a = 0; b = pi/3; eps = 0.001;
S1 = 0;
h = (b-a)/n;

for (i=1;i<=n;i++)
{
x = a + i*h - h/2;
S1 = S1 + sin(x)*h;
}

do
{
n = 2*n;
h = (b-a)/n;
S2 = 0;

for (i=1;i<=n;i++)
{
x = a + i*h - h/2;
S2 = S2 + sin(x)*h;
}

exact = fabs(S1-S2);
S1=S2;
}

while(exact>eps);
cout << "S = " << S2;
return 0;
}