A = (-5, -1)
B = (5, -1)
directrix = Line(A, B)
F = (0, 1)
d = 1 (slider from 1 to 10, step 0.05)
D = (0.26, 5.28)
E_1 = (-1.94, 5.36)
b = OrthogonalLine(F, directrix)
E = Intersect(directrix, b)
c = OrthogonalLine(B, directrix)
V = Midpoint(F, E)
g = Segment(F, V)
e = Circle(F, d)
h = Circle(B, d)
G = Intersect(h, c, 2)
i = Line(G, directrix)
I = Intersect(e, i, 2)
J = Intersect(e, i, 1)
a = 1
f(x) = (a * x^(2))
P_1 = (-4, 4)
P_2 = (-2, 1)
P_3 = (2, 1)
P_4 = (4, 4)
Q_1 = (-4, -1)
Q_2 = (-2, -1)
Q_3 = (2, -1)
Q_4 = (4, -1)