Comment by csomar
6 days ago
It is not interesting because there is no “real” solution (pun intended).
If you go to the complex plane, you are re-defining the plane. If you redefine the plane, then you can do anything. The puzzle is about confusing the observer who is expecting a solution in a certain dimension.
It's true that it might be unexpected that there is no real solution. I also wouldn't have intuited that from the problem statement itself.
However, it's not like you have to go out of your way to look for the complex numbers in some creative way. At some point while solving the quadratic equation you'll have to take the root of a negative number. So the only choice is to reach for the complex numbers, your hand is kinda forced.