CSC-111 In class Quadratic Equation Expression Solver

QuadraticEquationSolver.java

// Prof. A.C. Silvestri
// 10/13/18
// CSC-111 Intro to Java
// silvestri@stcc.edu
// Program to calculate roots of a quadratic

package chapter3;

import java.util.Scanner;

public class QuadraticEquationSolver {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		System.out.println("Welcome to the Quadratic Equation Solver!");

		System.out.print("Enter a: ");
		double a = input.nextDouble();
		if (a == 0) {
			System.out.println("Sorry. a cannot be 0");
		} 
		else {
			// Now enter your code here to calculate the solutions
			// provided the input values represent a valid quadratic
			// Remember there can be 0, 1, or 2 solutions.
			// Out results accordingly.	
			
			System.out.print("Enter b: ");
			double b = input.nextDouble();
			System.out.print("Enter c: ");
			double c = input.nextDouble();
			
			double sqrtExpr = b*b - 4 * a * c;
			if (sqrtExpr < 0) {
				System.out.println("There are 0 real roots.");
			}
			else if (sqrtExpr == 0) {
				double root = -b / (2 * a);
				System.out.printf("There is 1 root: %.2f\n", root);
			}
			else {
				double r1 = (-b + Math.sqrt(sqrtExpr)) / (2 * a);
				double r2 = (-b - Math.sqrt(sqrtExpr)) / (2 * a);
				System.out.printf("There are 2 roots: %.2f and %.2f\n", r1, r2);
			}
		}
		input.close();
	}

}