d = 1 (slider from -5 to 5, step 1)
c = 1 (slider from -5 to 5, step 1)
b = 1 (slider from -5 to 5, step 1)
a = 1 (slider from -5 to 5, step 1)
f(x) = (a * x^(3)) + (b * x^(2)) + (c * x) + d
f' = Derivative(f)
A = Point(f)
B: (x(A), f'(x(A)))