CS 201 - Computer Science I - Spring 2008 Assignment Statements

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Loyola College > Department of Computer Science > Dr. James Glenn > CS 201 > Examples and Lecture Notes > Assignment Statements

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RootFinder.java

/**
 * Finds the roots of a quadratic formula.
 */

public class RootFinder
{
    public static void main(String[] args)
    {
        // declare and initialize the coefficiants of the formula to solve
        // ((x+2)(x-2) here)
        
        double a;
        a = 1.0;

        double b;
        b = 0.0;

        double c;
        c = -4.0;

        // compute the discriminant

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

        //compute the roots

        double root1 = (-b + Math.sqrt(discriminant)) / (2 * a);
        double root2 = (-b - Math.sqrt(discriminant)) / (2 * a);

        // display the results

        System.out.println(root1 + " and " + root2);
    }
}

RootFinder2.java

import java.util.*;

/**
 * Finds the roots of a quadratic formula.
 */

public class RootFinder2
{
    public static void main(String[] args)
    {
	Scanner in;
	in = new Scanner(System.in);
			
        // declare and initialize the coefficiants of the formula to solve
        // ((x+2)(x-2) here)
        
	System.out.println("Enter the coefficient of the x^2 term:");
	double a;
        a = in.nextDouble();

	System.out.println("Enter the coefficient of the x term:");
        double b;
        b = in.nextDouble();

	System.out.println("Enter the coefficient of the constant term:");
        double c;
        c = in.nextDouble();

        // compute the discriminant

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

        //compute the roots

        double root1 = (-b + Math.sqrt(discriminant)) / (2 * a);
        double root2 = (-b - Math.sqrt(discriminant)) / (2 * a);

        // display the results

        System.out.println(root1 + " and " + root2);
    }
}

This code can also be downloaded from the files RootFinder.java, and RootFinder2.java.