f(x) = a x^3 + b x^2 + c x + d

d = 1.6 (slider from -5 to 5, step 0.1)
a = 0.7 (slider from -5 to 5, step 0.1)
b = -1.4 (slider from -5 to 5, step 0.1)
c = -2.5 (slider from -5 to 5, step 0.1)
f(x) = a * x^(3) + b * x^(2) + c * x + d
I = TurningPoint(f)
f'' = Derivative(f, 2)
ZH_1, ZH_2, ZH_3 = Root(f)
SZE_1, SZE_2 = Extremum(f)
f' = Derivative(f)
a_1 = Segment(SZE_1, (x(SZE_1), 0))
b_1 = Segment(SZE_2, (x(SZE_2), 0))
c_1 = Segment(I, (x(I), 0))
T2: "f(x) = " + (Polynomial[f])