According to the known hypothesis P(x, y), the trajectory equation of the moving point p is [(x-1|×| pf2 | = a2) 2+y2 ]× [(x+1) 2+y]. (2) Substitute (-x, -y) into the equation to verify that the equation is unchanged, that is, if (x, y) is on the curve, then (-x, -y) is also on the curve, so the curve C is symmetrical about the origin and the proposition is true; ③ because s △ pf1F2 =1/2 | pf1|| pf2 | sin ∠ f1pf2 = (a 2/2) sin ∠ f1pf2.