Let a (x1, Y1), B (X2, Y2) be two points on the parabola y2 = 2px (P > 0) and satisfy OA ⊥ ob. Then y1y2 is equal to () A. -4p2B. 4p2C. -2p2D. 2p2

Let a (x1, Y1), B (X2, Y2) be two points on the parabola y2 = 2px (P > 0) and satisfy OA ⊥ ob. Then y1y2 is equal to () A. -4p2B. 4p2C. -2p2D. 2p2

∵ a (x1, Y1), B (X2, Y2) are two points on the parabola y2 = 2px (P > 0), and satisfy OA ⊥ ob. ∵ KOA · kob = - 1, ∵ x1x2 + y1y2 = 0, ∵ (y1y2) 24p2 + y1y2 = 0, then y1y2 = - 4p2, so select a