O = (0, 0)
a = 2 (slider from -5 to 5, step 0.1)
M: (a, 0)
c = Circle(M, O)
A: ((2 * a), 0)
Q = Point(c)
b = Line(O, Q)
d = Circle(Q, A)
P, P' = Intersect(d, b)
Ortslinie1 = Locus(P, Q)
Ortslinie2 = Locus(P', Q)