/*
 * T01n01.java:  This is a straight-forward program that computes
 * the roots of a quadratic equation (ax^2 + bx + c = 0) given the
 * coefficients a, b, and c.
 *
 * As this is used as a first Java example for students new to Java,
 * it doesn't contain error handling.
 */

import java.util.*;   // Gives easy access to Java API's "util" package

public class T01n01
{
    final static double INCHES_TO_METERS = 0.0254; // 1 in. = 0.0254 meters
    final static double POUNDS_TO_KG = 0.4536;     // 1 lb. ~= 0.4536 kilograms

    public static void main (String [] args)
    {
        double   a,            // coefficient of the x^2 term
                 b,            // coefficient of the x^1 term
                 c,            // coefficient of the x^0 term
                 discriminant, // b^2 -4ac
                 root1, root2; // the roots of the quadratic equation

        Scanner keyboard = new Scanner (System.in);

        System.out.println("\nThis program will find the roots of the"
                         + " quadratic equation\nax^2 + bx + c = 0,"
                         + " assuming that a is not zero and that"
                         + " the discriminant\nis not negative.");

        System.out.print("\nEnter the value of a in the equation: ");
        a = keyboard.nextDouble();

        System.out.print("Enter the value of b in the equation: ");
        b = keyboard.nextDouble();

        System.out.print("Enter the value of c in the equation: ");
        c = keyboard.nextDouble();

        discriminant = Math.sqrt(b * b - 4 * a * c);
        root1 = (-b + discriminant) / (2*a);
        root2 = (-b - discriminant) / (2*a);

        System.out.println("\nThe roots of the quadratic equation\n"
                         + "(" + a + ")x^2 + (" + b + ")x + (" + c + ")\n"
                         + "are " + root1 + " and " + root2 + ".\n");

    }  // main

} // class T01n01