/*
Java Programming for Engineers
Julio Sanchez
Maria P. Canton
ISBN: 0849308100
Publisher: CRC Press
*/
// Java for Engineers
//Filename: QuadSolv
//Reference: Chapter 24
//Description:
// Applying the quadratic formula
//Requires:
// Keyin class in current directory
strictfp class QuadSolv
{
public static void main(String[] args)
{
double a, b, c, discr, root1, root2;
// Apllying the quadratic formula
// Obtain sides from user
System.out.println("Applying the quadratic formula");
a = 1d;
b = 2d;
c = 3d;
// Solve the discriminant (SQRT (b^2 - 4ac)
discr = Math.sqrt((b * b) - (4 * a * c));
System.out.println("Discriminant = " + discr);
// Determine number of roots
// if discr > 0 equation has 2 real roots
// if discr == 0 equation has a repeated real root
// if discr < 0 equation has imaginary roots
// if discr is NaN equation has no roots
// Test for NaN
if(Double.isNaN(discr))
System.out.println("Equation has no roots");
if(discr > 0)
{
System.out.println("Equation has 2 roots");
root1 = (-b + discr)/2 * a;
root2 = (-b - discr)/2 * a;
System.out.println("First root = " + root1);
System.out.println("Second roor = " + root2);
}
if(discr == 0)
{
System.out.println("Equation has 1 root");
root1 = (-b + discr)/2 * a;
System.out.println("Root = " + root1);
}
if(discr < 0)
System.out.println("Equation has imaginary roots");
}
}