I would have done that slightly differently. From
, add
to both sides to get
. Squaring both sides of that you get
. You still have the square root form the "cross term" but since you don't have both square roots on the same side, it's a little simpler. That can be reduced, by canceling the "x" terms on both sides and canceling the "-4" and "4", to
which reduces to
. Now square both sides again to get x- 4= 4.
Notice that while e^(i*pi)'s equation
looks like a quadratic, it is not be cause the [itex]x^2[/itex] terms on each side will cancel.