Write a Java program to find all roots of a quadratic equation

Find all roots of a quadratic equation

A quadratic equation is same as middle term, but quadratic equation can find exact value of x1 and x2.

• => x^2 - 5x + 6 = 0
• Here, a = 1, b = -5 and c = 6
• => x^2 - 3x - 2x + 6 = 0
• => x(x - 3) - 2(x - 3) = 0
• => x = 3, 2

Sample Output

Find all roots of a quadratic equation.

Value of a: 1
Value of b: -5
Value of c: 6
x1: 3.0
x2: 2.0

Java-Source Code

//package ifelsejava;

import java.util.Scanner;
import static java.lang.Math.*;

public class Main {

    public static void main(String[] args) {

        int a, b, c;
        double x1, x2, root;

        Scanner input = new Scanner(System.in);

        System.out.println("Find all roots of a quadratic equation.\n");

        System.out.print("Value of a: ");
        a = input.nextInt();
        
        System.out.print("Value of b: ");
        b = input.nextInt();
        
        System.out.print("Value of c: ");
        c = input.nextInt();
        
        root = sqrt(pow(b, 2) - (4 * a * c));
        x1 = (- b + root) / (2 * a);
        x2 = (- b - root) / (2 * a);
        
        System.out.println("x1: " + x1 + "\nx2: " + x2);
    }
}

Sample Output

Find all roots of a quadratic equation.

Value of a: 1
Value of b: 4
Value of c: 2
x1: -0.5857864376269049
x2: -3.414213562373095