Quadratic.java

package org.drip.zen.equation;

/*
 * 1) a, b, c
 * 2) Constructor
 * 3) Retrieve a, b, c
 * 4) Find Roots
 * 5) Introduce concept of NULL
 */

public class Quadratic {
    private double _a;
    private double _b;
    private double _c;

    public Quadratic (double a, double b, double c)
    {
        _a = a;
        _b = b;
        _c = c;
    }

    public double a()
    {
        return _a;
    }

    public double b()
    {
        return _b;
    }

    public double c()
    {
        return _c;
    }

    public double[] findRoots()
    {
        double bSquaredMinus4ac = _b * _b - 4 * _a * _c;

        if (bSquaredMinus4ac < 0) return null;

        double[] roots = new double[2];
        roots[0] = (-1. * _b + Math.sqrt (bSquaredMinus4ac)) / (2 * _a);
        roots[1] = (-1. * _b - Math.sqrt (bSquaredMinus4ac)) / (2 * _a);
        return roots;
    }
}