a = 0.06999999999999992 (slider from -5 to 5, step 0.01)
f(x) = 2 x - a x³
A, B, C = Intersect(f, xAxis)
b = Segment(B, C)
c = OrthogonalLine(C, b)
d = Circle(C, B)
D, E = Intersect(d, c)
e = Line(E, xAxis)
F = Intersect(e, yAxis)
P, b_1, c_1, e_1, f_1 = Polygon(B, C, E, F)