C5X1_QuadraticEquation.java

//QuadraticEquation.java    MrG 2011.1024
public class QuadraticEquation
{
    private int a;
    private int b;
    private int c;

    /**
    Constructor: instantiate the integer coefficients of the equation
    @param a coefficient of x^2
    @param b coefficient of x^1
    @param c coefficient of x^0
    */
    public QuadraticEquation(int a, int b, int c)
    {
        this.a = a;
        this.b = b;
        this.c = c;
    }

    /**
    Accessor: calculates the discriminant
    @return b^2-4ac
    */
    public int getDisc()
    {
        return b*b - 4*a*c;
    }

    /**
    Accessor: calculates one root
    @return (-b+sqrt(d))/(2a)
    */
    public double getRoot1()
    {
        return (-b+Math.sqrt(getDisc()))/(2*a);
    }

    /**
    Accessor: calculates another root
    @return (-b-sqrt(d))/(2a)
    */
    public double getRoot2()
    {
        return (-b-Math.sqrt(getDisc()))/(2*a);
    }

    /**
    Accessor: true iff roots are real
    @return getDisc()>=0
    */
    public boolean hasSolutions()
    {
        if(getDisc()<0)
        {
            return false;
        }
        else
        {
            return true;
        }
    }
}