A free trade area is a group of countries that have agreed to eliminate tariffs, quotas and preferences on most goods between them. Unlike a customs union, members of a free trade area do not have the same policies with respect to non-members. Free trade areas include NAFTA and EFTA.
... If the discriminant is positive, then there are two different solutions x, both of which are real. (Geometrically, this means that the parabola intersects the x-axis ...