For hyperbola, which is positive, X 2 or Y 2, its dividing line is A 2 (the square of A), negative is B 2, the focal coordinates of hyperbola are (c, 0) and (-c, 0), and A, B and C of hyperbola satisfy A 2+B 2 = C 2.

a^2=4？ B 2 = 12, then C 2 = 16,? c=4

So the focal coordinate is (4,0) (-4,0) and the right focal point is (4,0).