QuadraticEquation.java

//Program to solve quadratic equations (use if, else if and else).

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

public class QuadraticEquation
{
	public static void main(String args[])
	{
		Scanner reader = new Scanner(System.in);
		System.out.print("\nEnter the coeffiect for quadratic term: ");
		double a = reader.nextDouble();
		System.out.print("\nEnter the coeffiect for linear term: ");
		double b = reader.nextDouble();
		System.out.print("\nEnter the constant term: ");
		double c = reader.nextDouble();
		reader.close();
		double d = b*b - 4*a*c;

		if (d > 0)
		{
			double root1 = (-b + Math.pow(d, 0.5))/(2*a);
			double root2 = (-b - Math.pow(d, 0.5))/(2*a);
			System.out.print("Both roots are real which are " + root1 + " and " + root2);
		}
		else if (d == 0)
		{
			System.out.print("Both roots are real and equal which is " + -b/(2*a));
		}
		else
		{
			System.out.print("Both roots are imaginary.");
		}
	}
}
//Output:
//Enter the coeffiect for quadratic term: 1
//
//Enter the coeffiect for linear term: 2
//
//Enter the constant term: 1
//Both roots are real and equal which is -1.0