https://www.geogebra.org/haftendorn
Haftendorn, Buch (Springer):
Kurven erkunden und verstehen
Kap 9.5.5  S.295 Afg. 9.14
www.kurven-erkunden-und-verstehen.de

Ha 2017

a_1: 1
a_2 = 0
a_3: -1
a_4 = 0
a_5 = 0
a_6 = -4
k: 2
A = Intersect(xAxis, yAxis)
h: ((a_1 * k^(4)) * x^(2)) + (((a_2 * k^(4)) * x) * y) + ((a_3 * k^(4)) * y^(2)) + (((a_4 * k^(2)) * x) * (x^(2) + y^(2))) + (((a_5 * k^(2)) * y) * (x^(2) + y^(2))) + (a_6 * (x^(2) + y^(2))^(2)) = 0
c_3: (a_1 * x^(2)) + ((a_2 * x) * y) + (a_3 * y^(2)) + (a_4 * x) + (a_5 * y) + a_6 = 0
p = Circle(A, k)
C, D = Focus(c_3)
g = false