g(x) = (cos(x) * cos(x))
a = 3.9 (slider from 0 to 20, step 0.1)
A = Intersect(xAxis, yAxis)
B = Point(Circle[A, a])
f = Segment(A, B)
C = Point(Circle[A, a])
h = Segment(A, C)
i = OrthogonalLine(C, xAxis)
j = OrthogonalLine(B, xAxis)
D = Intersect(g, i, (-3.9, 0.5269777102813249))
E = Intersect(g, j, (3.9, 0.5269777102813249))
k = Segment(D, C)
l = Segment(E, B)