Ortslinie

f(x) = x * (4 - x)
Q = Point(f)
a = Tangent(Q, f)
ab = 2.5 (slider from -5 to 5, step 0.1)
c = Circle(Q, ab)
P, B = Intersect(c, a)
u = Vector(Q, P)
Ortslinie1 = Locus(P, Q)
b = false