Answers for "QuadricEquation testDome"

QuadricEquation testDome

public class QuadraticEquation {
    public static Roots findRoots(double a, double b, double c) {
    	Roots root = new Roots(0,0);
    	double root1, root2;
    	if(a==0 ||b==0||c==0) return root;
    	// calculate the determinant (b2 - 4ac)
        double determinant = (b * b) - (4 * a * c);
        if (determinant > 0) {
            // two real and distinct roots
            root1 = (-b + Math.sqrt(determinant)) / (2 * a);
            root2 = (-b - Math.sqrt(determinant)) / (2 * a);
//           System.out.format("root1 = %.2f and root2 = %.2f", root1, root2);
          } // check if determinant is equal to 0
       	else if (determinant == 0) {
           // two real and equal roots then determinant is equal to 0
            // so -b + 0 == -b
            root1 = -b / (2 * a);
            root2 = root1;
          } else {
            // roots are complex number and distinct
            root1= -b / (2 * a);
            root2 = Math.sqrt(-determinant) / (2 * a);
          }
        root = new Roots(root1,root2);
    	return root;
    }
    
    public static void main(String[] args) {
        Roots roots = QuadraticEquation.findRoots(2, 10, 8);
        System.out.println("Roots: " + roots.x1 + ", " + roots.x2);
//        roots = QuadraticEquation.findRoots(15, 68, 3);
//        System.out.println("Roots: " + roots.x1 + ", " + roots.x2);
      roots = QuadraticEquation.findRoots(1, -18, 81);
      System.out.println("Roots: " + roots.x1 + ", " + roots.x2);

    }
}

class Roots {
    public final double x1, x2;

    public Roots(double x1, double x2) {         
        this.x1 = x1;
        this.x2 = x2;
    }
}