https://www.geogebra.org/haftendorn
Haftendorn, Buch (Springer):
Kurven erkunden und verstehen
Kap 9.6.4  S. 305 Afg. 9.18
www.kurven-erkunden-und-verstehen.de

Ha 2017

a = 1.5 (slider from -5 to 5, step 0.1)
f(x) = (a * cosh(x / a))
P = Point(f)
g = Tangent(P, f)
h = OrthogonalLine(P, g)
i = OrthogonalLine(P, xAxis)
X = Intersect(i, xAxis)
c = Circle(P, y(P)^(2) / a)
D, M = Intersect(c, h)
j = Segment(P, X)
d = Circle(P, X)
e = Circle(P, a)
A = Intersect(e, h, 1)
B = Intersect(d, g, 1)
k = Segment(A, B)
l = OrthogonalLine(B, k)
G = Point(d)
p = CircleArc(P, G, X)
Vieleck1, f_1, c_1, e_1 = Polygon(A, M, B)
q = Circle(M, P)
S: (0, a)
O = Intersect(xAxis, yAxis)
m = Segment(S, O)
n = Segment(P, A)
r = Segment(P, B)
b = false
Ortslinie1 = Locus(M, P)