code: public Complexd div(double x, double y) {
          final double d = x * x + y * y;
          return new Complexd(
                  (this.x * x + this.y * y) / d,
                  (this.y * x - this.x * y) / d);
      }
docs: Divides this complex by the double components of another one.
  
  @param x The x (real) component of the complex to divide with
  @param y The y (imaginary) component of the complex to divide with
  @return The quotient of the two complexes