f(x) = ((((((((((x * (x - 1)) * (x + 1)) * (x - 2)) * (x + 2)) * (x - 3)) * (x + 3)) * (x - 4)) * (x + 4)) * (x - 5)) * (x + 5) / 10000)
P = Point(f)
p = 1.81 (slider from 0 to 6.28318531, step 0.01)
s: (p, 0)
P': P + s
u = Vector(P, P')