Calling a method ---please help

Question

Hi everyone, I'm new to the forums, and completely new to java,. I've been searching for hours (online and in books) on how to call a method while passing parameters. I still haven't figured it out. I'm sure it's really easy, but I need some help.
This program is for evaluating the quadratic formula. I can't seem to return x1 and x2 from lines 73 and 78 (labeled in code) from method quad to lines 39, 40, and 46. It will compile and run, but it will not display x1 and/or x2.
Please help, and thanks in advance.
Am I even close?
import java.util.*;
import java.lang.*;
import javax.swing.JOptionPane;
    public class test
      static Scanner console = new Scanner(System.in);
       public static void main(String[] args)
        //Declare variables
        double a = 0;
        double b = 0;
        double c = 0;
        double d = 0;
         //Asking the user for input
        inputA = JOptionPane.showInputDialog(null, "enter number for x^2");
        inputB = JOptionPane.showInputDialog(null, "enter number for x";
        inputC = JOptionPane.showInputDialog(null, "enter number for constant");
        //Parsing string  to double
        a = Double.parseDouble(inputA);
        b = Double.parseDouble(inputB);
        c = Double.parseDouble(inputC);
        //calculating discriminant
        d = (Math.pow(b,2) - (4 * a * c));
         //Checking to see if the discriminant is less than zero - has two imaginary roots
         if (d < 0)
               JOptionPane.showMessageDialog(null, "There are two imaginary roots.");
            }//end checking to see if the discriminant is less than zero - has two imaginary roots
     //calling method quad
            if (d > 0)
     quad(a, b, c, 1);                              //line 39
     quad(a, b, c, 2);                              //line 40
                            JOptionPane.showMessageDialog(null, "There are two real roots. They are root 1 = "
                                           + x1 + " , and root 2 = " + x2 + ".");
            else if (d == 0)
                      quad(a, b, c, 1);                             //line 46
                             JOptionPane.showMessageDialog(null, "There is a single (repeated) root.  It is " + x1);
         //starting method quad
     public static double quad (double a, double b, double c, int n)
         double d = 0;                         //value for d - discriminant
         double x1 = 0;                         //value for x - solving for x
         double x2 = 0;                         //value for -x - solving for negative x
           //Checking if discriminant equals zero or is larger than zero
         if (d == 0)
                 n = 1;
         else
                 n = 2;
           //Checking if n equals zero
         if (n == 1)
                 x1 = ((-b) + (Math.sqrt((Math.pow(b,2))-(4 * a* c))) / (2 * a));
                 return x1;                          //line 73
         else
                 x2 = ((-b) - (Math.sqrt((Math.pow(b,2))-(4 * a* c))) / (2 * a));
                 return x2;                         //line 78
     }//end method quad

Answer 1

Man, you guys/gals are great! You notice everything...I sure appreciate all the help so far. I've updated a few things, but I still can't get x1 in the method to pass the right input to line 39. For instance, if I set a=2, b=4, and c=-30, then x1 should = 3 and x2 should =-5, but both keep showing -5. They are always equal for some reason, even when they are not supposed to be.
I see what you were saying with d always equalling zero. I was looking in the main where it doesn't always = zero, but in the method it was always set to zero. Thanks...good eye!
num1 = quad(a, b, c, 1);                              //line 39
num2 = quad(a, b, c, 2);                              //line 40
JOptionPane.showMessageDialog(null, "There are two real roots. They are root 1 = "+ num1 + " , and root 2 = " + num2 + ".");I also added this to the method so d won't always = zero
d = (Math.pow(b,2) - (4 * a * c));I also have all of the variables declared at the top, but I forgot to copy and paste all of them and I updated the System.exit(0) to close the JOptionPane along with extra } 's to close the program correctly.
Again, thanks a bunch.