A, B are points on the x-axis, y-axis respectively. If OA = a, OB = b, what are the coordinates of P, the midpoint of AB? If the line AB moves so that the area of the triangle OAB is always 2c^2, find the locus of P. Show that the line AB touches the locus of AB.

Alright so i've found the midpoint = (a/2, b/2). But how exactly do I find its locus with the fact about the area of the triangle???

Please help?