First of all, the set A is not an empty set, that is, the quadratic curve y = x 2-4mx2m6y intersects with the X axis. Set b represents the negative semi-axis of the coordinate axis X, which is discussed in different cases: the conic that intersects the conic Y = X 2-4mx2m6y = the axis of symmetry X of x 2-4 mx2m6y; 0, the quadratic equation x 2-4mx2m6 = 0 must have a positive solution and a negative solution, namely x 1 * x2.