mostra ellisse

F_1 = (0.4, 0)
F_2 = (-0.4, 0)
α = 3.752457891787808 rad (slider from 0 to 6.283185307179586, step 0.08726646259971647)
A = Point(xAxis)
A' = Rotate(A, α, F_1)
β = Angle(A, F_1, A')
a = Line(F_1, A')
B = Intersect(xAxis, yAxis)
c = Circle(F_1, Segment[B, A])
C = Intersect(c, a, 1)
b = Line(C, F_2)
D = Midpoint(C, F_2)
d = OrthogonalLine(D, b)
P = Intersect(d, a)
e = Circle(P, C)
f = Ellipse(F_1, F_2, Radius[c] / 2)
g = true