package renshu1;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;

public class ex2_5 extends JApplet {
  double a, b, c;
  public void init() {
    a = Double.parseDouble(JOptionPane.showInputDialog("a（≠0）を入力してください"));
    b = Double.parseDouble(JOptionPane.showInputDialog("bを入力してください"));
    c = Double.parseDouble(JOptionPane.showInputDialog("cを入力してください"));
  }

  public void paint(Graphics g) {
    g.drawString(a + "x^2 + " + b + "x + " + c + " = 0 の解は", 20, 20);
    double d = b * b - 4.0 * a * c;
    if (d > 0.0) {
      g.drawString("x1 = " + (-b + Math.sqrt(d)) / (2.0 * a), 20, 50);
      g.drawString("x2 = " + (-b - Math.sqrt(d)) / (2.0 * a), 20, 70);
    }
    else if (d == 0.0) {
      g.drawString("x = " + (-b) / (2.0 * a), 20, 50);
    }
    else {
     g.drawString("x = " + (-b) / (2.0 * a) + " ± " +  Math.sqrt(-d) / (2.0 * a) + "i", 20, 50);
   }
 }
}