If AX^2 + BX + C = DX^2 + EX + F, then parabolas Y = AX^2 + BX + C and Y = DX^2 + EX + F 有交点.
Visually, if these two parabolas should cross each other, then there should be a set or sets of (X, Y) that fulfill both parabolas Y = AX^2 + BX + C and Y = DX^2 + EX + F.