r(\theta)=a  \tan (Pi/4-t/2)

Polarkoord. 3. Formel

O = (0, 0)
a = 4 (slider from -5 to 5, step 0.1)
A: (a, 0)
b = OrthogonalLine(A, xAxis)
Q = Point(b)
c = Line(O, Q)
d = Circle(Q, A)
P, P' = Intersect(d, c)
Ortslinie1 = Locus(P, Q)
Ortslinie2 = Locus(P', Q)
t = -0.2 (slider from -5 to 5, step 0.1)
Pol: ((a * tan(π / 4 - t / 2)); t)
Ortslinie3 = Locus(Pol, t)