The directrix is located at y = -1
The focus is locate at (0,e) where e is the eccentricity.
The slider for d will give you points that are d units from the directrix
and ed units from the focus.

Move the slider to generate the curve.

To erase the trace go to “Refresh Views”  in the view menu.

Change the eccentricity by typing e = whatever in the input window.

Experiment with different values of e and observe what happens

e = 0.8
A = (0, -1)
a = OrthogonalLine(A, yAxis)
C = Point(a)
b = OrthogonalLine(C, a)
d = 1 (slider from 1 to 20, step 0.1)
c = Circle(C, d)
F: (0, e)
f = Circle(F, (d * e))
D_1 = Intersect(c, b, 1)
g = OrthogonalLine(D_1, b)
E = Intersect(f, g, 2)
D = Intersect(f, g, 1)