Funkcja kwadratowa

/**
 * Created by Hylus on 2017-02-28.
 */

import java.util.Scanner;

public class organizacyjne
{
    public static void main( String[] args)
    {
        System.out.printf("y=ax^2 + bx + c\n");
        System.out.printf("Podaj a b c x1 x2 dx\n"); //x1 i x2 to zakres, dx co ile ma sie zmieniac

        Scanner input = new Scanner (System.in);
        double a = input.nextDouble();
        double b = input.nextDouble();
        double c = input.nextDouble();

        double delta = (b*b)-(4*a*c);
        if (delta>0) {

            double x2;
            double x1;

            x1 = input.nextDouble();
            do {
                x2 = input.nextDouble();
            } while (x2 < x1);

            double dx = input.nextDouble();

            System.out.printf("Reprezentuje funkcje: y=%.2f*x^2+%.2f*b + %.2f\n", a, b, c);
            System.out.printf("Miejsca zerowe to %.2f i %.2f\n", (-b - Math.sqrt(delta)) / (2 * a), (-b + Math.sqrt(delta)) / (2 * a));

            System.out.printf("\tX\t|\tY\n");
            for (double i = x1; i <= x2; i = i + dx) {
                System.out.printf("%.2f\t|\t%.2f\n", i, a * (i * i) + b * i + c);
            }
        }
        else
        {
            System.out.printf("delta < 0");
        }

    }
}