import javax.swing.JOptionPane;

public class Newton {
    public static  double eps, xo;
    public static final int MAXIT = 200;
    public static  int counter;
    public Newton() {
    }


    public static void main(String[] args) {
        eps = Double.parseDouble(JOptionPane.showInputDialog("enter eps please:"));
        xo = Double.parseDouble(JOptionPane.showInputDialog("enter first try please:"));
        counter = 0;
        System.out.println(newton(xo));
         System.out.print("found in  " + counter + " eterations");
    }
    public static double newton(double x) {
        double newX = x - (f(x) / df(x));
        if (Math.abs(newX - x)< eps) {
            return newX;
        }
        counter++;
        if (counter == MAXIT) {
            System.out.print("function has no roots");
            return 0.0;
        }
        return newton(newX);
    }

    public static double f(double x) {
        return x*x*x - x*x - 2*x +1;
    }
    public static double df(double x) {
        return 3*x*x - 2*x - 2;
    }

}