The Quadratic equation calc written in java(more secure)

/*program starts here*/
// <sonu-fold defaultstate="collapsed" desc="it is a quadratic equation calculator">
class quad {

    private double a, b, c;

    void test(double i, double j, double k) {
        a = i;
        b = j;
        c = k;
        double d = b * b - (4 * a * c);
        double r = Math.sqrt(d);

        double x = (-b + r) / 2 * a;
        double y = (-b - r) / 2 * a;

        System.out.println("the roots are " + x + " and " + y);

    }
}

class real {

    public static void main(String args[]) {
        quad myquad1 = new quad();
        System.out.println("The equation is in the form of ax^2+bx+c=0");
        myquad1.test(/*enter a b& c hereseperated by comma*/1,2,-8 );
    }
}// </sonu-fold>