#include <iostream>
#include <cmath>
 
using namespace std;
 
double f(double x)
{
    return sin(x);
}
 
double prostokaty(double a, double b, int n)
{
    double dx = (b - a) / n;
    double x = a;
    double s = 0.0;
 
    for (int i = 1; i <= n; i++)
    {
        x = x + dx;
        s = s + dx * f(x);
    }
 
    return s;
}
 
int main()
{
    double a = 0.0;
    double b = 3.14;
 
    double s1 = prostokaty(a, b, 10);
    double s2 = prostokaty(a, b, 100);
 
    cout << "S1 (n = 10)  = " << s1 << endl;
    cout << "S2 (n = 100) = " << s2 << endl;
 
    return 0;
}
 

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