f(x)=-k(\frac{2}{a^3}x^4-\frac{3}{a^2}x^3+x)

a = 7 (slider from 0.5 to 10, step 0.5)
k = 0.46 (slider from 0.01 to 1, step 0.01)
f(x) = -k * (2 / a^(3) * x^(4) - 3 / a^(2) * x^(3) + x)
A = (-0.25, -0.5)
B = (0.25, -0.5)
C = Intersect(f, xAxis, 2)
Vieleck1, b, c, a_1 = Polygon(C, A, B)
D, E, F = Intersect(f, xAxis)
d_1 = 0.6
G = Point(Circle[F, 0.6])
d = Segment(F, G)
e = OrthogonalLine(F, xAxis)
g = OrthogonalLine(G, xAxis)
H = Point(e)
I = Point(e)
h = Line(H, xAxis)
i = Line(I, xAxis)
J = Intersect(g, h)
K = Intersect(g, i)
p = If(x < 0, f, 1000)
q = If(0 < x < a, f, 1000)
r = If(x > a, f, 1000)
Vieleck2, h_1, j, k_1, i_1 = Polygon(H, J, K, I)
L, h_2, j_1, k_2, i_2 = Polygon(H, J, K, I)