discriminant method

@override Complex discriminant()

The polynomial discriminant, if it exists.

Implementation

@override
Complex discriminant() {
  final p1 = c * c * b * b;
  final p2 = d * b * b * b * const Complex.fromReal(4);
  final p3 = c * c * c * a * const Complex.fromReal(4);
  final p4 = a * b * c * d * const Complex.fromReal(18);
  final p5 = d * d * a * a * const Complex.fromReal(27);

  return p1 - p2 - p3 + p4 - p5;
}