kek 12

#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    double epsilon;
    cout << "Enter epsilon: ";
    cin >> epsilon;

    double x;
    cout << "Enter X: ";
    cin >> x;

    int iterations = 1;
    double prev = 0;
    double current = x;
    while (fabs(current - prev) > epsilon) {
        prev = current;
        current *= (1 - (x * x) / (iterations * iterations * M_PI * M_PI));

        iterations++;
    }

    cout << "Iterations: " << iterations << endl;
    cout << "Result: " << current << endl;
    cout << "Fact difference: " << fabs(current - sin(x)) << endl;

    return 0;
}