C Programs Tutorials | IT Developer
IT Developer

Java Programs

Share with a Friend
Previous
HOME
Next

Operators & Expressions

Java Program: Solve Quadratic Equation for Real & Imaginary Roots

Java 
import java.util.Scanner;


 


class QuadraticEquationSolver {


    public static void main(String[] args) {


        Scanner sc = new Scanner(System.in);


 


        System.out.print("Enter coefficient a: ");


        double a = sc.nextDouble();


 


        System.out.print("Enter coefficient b: ");


        double b = sc.nextDouble();


 


        System.out.print("Enter coefficient c: ");


        double c = sc.nextDouble();


 


        double discriminant = (b * b) - (4 * a * c);


 


        System.out.println("\nDiscriminant = " + discriminant);


 


        if (discriminant > 0) {


            // Real and distinct roots


            double r1 = (-b + Math.sqrt(discriminant)) / (2 * a);


            double r2 = (-b - Math.sqrt(discriminant)) / (2 * a);


 


            System.out.printf("Roots are Real and Distinct:%n");


            System.out.printf("Root 1 = %.2f%n", r1);


            System.out.printf("Root 2 = %.2f%n", r2);


 


        } else if (discriminant == 0) {


            // Real and equal roots


            double r = -b / (2 * a);


 


            System.out.println("Roots are Real and Equal:");


            System.out.printf("Root = %.2f%n", r);


 


        } else {


            // Imaginary roots


            double realPart = -b / (2 * a);


            double imagPart = Math.sqrt(-discriminant) / (2 * a);


 


            System.out.println("Roots are Imaginary:");


            System.out.printf("Root 1 = %.2f + %.2fi%n", realPart, imagPart);


            System.out.printf("Root 2 = %.2f - %.2fi%n", realPart, imagPart);


        }


 


        sc.close();


    }


}

Output

OUTPUT 1: (Real & Distinct Roots)
 INPUT 
Enter coefficient a: 1
Enter coefficient b: -3
Enter coefficient c: 2

OUTPUT 
Discriminant = 1.0
Roots are Real and Distinct:
Root 1 = 2.00
Root 2 = 1.00

OUTPUT 2:(Real & Equal Roots)
 INPUT 
Enter coefficient a: 1
Enter coefficient b: 2
Enter coefficient c: 1

OUTPUT 
Discriminant = 0.0
Roots are Real and Equal:
Root = -1.00

OUTPUT 3: (Imaginary / Complex Roots)
 INPUT 
Enter coefficient a: 1
Enter coefficient b: 2
Enter coefficient c: 5

OUTPUT 
Discriminant = -16.0
Roots are Imaginary:
Root 1 = -1.00 + 2.00i
Root 2 = -1.00 - 2.00i

Explanation

  1. Input Coefficients

          The program reads a, b, and c from the user for the equation:

                           ax2 + bx + c = 0

  1. Compute Discriminant

           double discriminant = (b * b) - (4 * a * c);

                           Java Programs

           The discriminant determines the type of roots.

  1. Case 1 → Real & Distinct Roots (D > 0)

                         Java Programs

           Both roots are different real numbers.

  1. Case 2 → Real & Equal Roots (D = 0)

                         Java Programs

           Both roots are equal.

  1. Case 3 → Imaginary Roots (D < 0)

                         Java Programs

           The program prints roots as complex numbers:

               realPart ± imagPart i

 

Key Concepts Used

✔ Quadratic formula
✔ Discriminant
✔ Math.sqrt()
✔ Handling complex (imaginary) numbers
✔ if–else decision making
✔ Formatted output using printf

 

Previous
Next