#include <bits/stdc++.h>
using namespace std;
// f(x) = 3x - cos(x) - 1
double f(double x) {
    return 3*x - cos(x) - 1;
}

signed main() {
    ios_base::sync_with_stdio(false);  cin.tie(NULL);
    int iter = 0;
    double tol = 0.0001;
    cout << "Iter\t" << "Root\n"; 
    
    // Root lies between [0..1]
    double a = 0, b = 1;
    double c, prev = 0;
    do {
        c = (a * f(b) - b * f(a)) / (f(b) - f(a));
        cout << ++iter << "\t" << c << endl;
        if (fabs(f(c)) < tol) {
            break;
        }

        if (f(c) * f(a) < 0) {
            b = c;
        } else {
            a = c;
        }
        if (fabs(c - prev) < tol) {
            break;
        }

        prev = c;

    } while (fabs(b - a) > tol);

}