d = 70.1 (slider from -5 to 100)
c = 22 (slider from -5 to 30)
b = -4 (slider from -10 to 5)
a = 0 (slider from 0 to 5, step 0.05)
h(x) = (a * x^(4)) + (b * x^(3)) + (c * x^(2)) + (d * x)
f(x) = If[0 ≤ x ≤ 4, h(x)]