How to solve imaginary quadratic roots in java?

Question

I've been trying a lot but it only shows NaN. I'm not sure if I'm doing the right thing.

 class Imaginary{
    
     double a = 2;
     double b = 3;
     double c = 5;
     double result = b * b - 4 * a * c;
    
     if(result < 0.0){
      double im1 = -2 + (Math.sqrt((result))/ 10);
      double im2 = -2 - (Math.sqrt((result))/ 10);
    
    
      System.out.println("x = " + imaginary1 + " or x = " + imaginary2);
            }
 }

Answer 1

You need to take negate result to make it positive before taking the square root (taking square roots of negative numbers always results in NaN) and append "i" before printing.

double real = -b / (2*a);
double img = Math.sqrt(-result) / (2*a);
System.out.println("x = " + real + " + " + img +"i or x = " + real + " - " + img + "i");

Answer 2

You shouldn't use sqrt(result) since it will always result in you taking the square root of a negative number (that is your condition for result). Instead try to use a formula (eg completing the square).

Hope it answers your question :)