b

f(b)

f(a)

a

b

M

c

f(x) = 0.02 * (x - 16) * (x - 13) * (x - 9) + 3
A = Intersect(f, a, 1)
B = Intersect(f, b, 1)
c = OrthogonalLine(A, yAxis)
d = OrthogonalLine(B, yAxis)
C = (39, 9)
D = Intersect(d, yAxis)
E = Intersect(c, yAxis)
F = Point(a)
G = Intersect(b, xAxis)
H = Point(yAxis)
e = OrthogonalLine(H, yAxis)
I = Intersect(f, e, 1)
g = OrthogonalLine(I, xAxis)
J = Intersect(g, xAxis)
h = Segment(H, I)
i = Segment(I, J)