Astroide entsteht

https://www.geogebra.org/haftendorn
Haftendorn, Buch (Springer):
Kurven erkunden und verstehen
Kap 4.4.5.2: S. 125

Ha 2016

a: 2
b: 1
Q = Point(xAxis)
c = Circle(Q, a + b)
A, B = Intersect(c, yAxis)
e = Segment(B, Q)
P: ((x(Q) * a / (a + b)), (y(B) * b / (a + b)))
elliOben = Locus(P, Q)
f = Segment(Q, A)
t: a / (a + b)
P' = Mirror(P, xAxis)
elliUnten = Locus(P', Q)
es: e
fs: f
d = false
g = false