(2)② Let the coordinates of point F be (m, n), and the analytical formula of parabola be y = f (x) =-x 2+3, because e (m, 3), C(√3, 3), e' and c' are symmetrical about point F respectively, so e' (m, 2n-3).

Therefore, e ′ (t, 3-2t 2), c ′ (2t-√ 3, 3-2t 2), because △ Fe ′ c ′ falls in the figure (including the boundary) surrounded by the X axis and the parabolic part above the X axis, so y (c ′) = y (e ′) ≥ 0, y (.