a = 2 (slider from 0.2 to 5, step 0.05)
f(x) = (0.003 * x^(4)) - (0.075 * x^(3)) + (0.55 * x^(2))
f''(x) = f''(x)
C, D = Intersect(f'', xAxis)
B: (x(C) + 1 / a, f(x(C) + 1 / a))
A: (x(C), f(x(C)))
g = Line(A, B)
texte1: "Pente :\\\frac{f(a)-f(b)}{a-b}\\=\frac{" + (LaTeX[y(A)]) + "-" + (LaTeX[y(B)]) + "}{" + (LaTeX[x(A)]) + "-" + (LaTeX[x(B)]) + "}\\=" + (LaTeX[(y(A) - y(B)) / (x(A) - x(B))]) + ""