Java Program to Display the Roots of a Quadratic Equation


To write a java program that displays the roots of a quadratic equation ax2+bx=0. Calculate the
discriminate D and based on the value of D, describe the nature of the root.


import java.util.*;
class quadraticdemo
public static void main(String[] args)
int a, b, c;
double r1, r2, D;
Scanner s = new Scanner(;
System.out.println("Given quadratic equation:ax^2 + bx + c");
System.out.print("Enter a:");
a = s.nextInt();
System.out.print("Enter b:");
b = s.nextInt();
System.out.print("Enter c:");
c = s.nextInt();
D = b * b - 4 * a * c;
if(D > 0)
System.out.println("Roots are real and unequal");
r1 = ( - b + Math.sqrt(D))/(2*a);
r2 = (-b - Math.sqrt(D))/(2*a);
System.out.println("First root is:"+r1);
System.out.println("Second root is:"+r2);
else if(D == 0)
System.out.println("Roots are real and equal");
r1 = (-b+Math.sqrt(D))/(2*a);
System.out.println("Roots are imaginary");


Given quadratic equation:ax^2 + bx +c 
Enter a:2
Enter b:3
Enter c:1
Roots are real and unequal
First root is:-0.5
Second root is:-1.0

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