a = 2 (slider from -5 to 5, step 0.1)
c: y = 3 * x * x - 12 * x + 3 * a + 9
f(x) = 4 * sin((4 * x - x * x - a - 3) / 2) * cos((x * x - 2 * x - a - 1) / 2)
g(x) = sin((4 * x - x * x - a - 3) / 2)
h(x) = cos((x * x - 2 * x - a - 1) / 2)
k: y = x * x - 2 * x - a - 1
p: y = (4 * x - x * x - a - 3) / 2
q(x) = 2 * sin(x - a - 2)
r(x) = 2 * sin(3 * x - x * x - 1)
A, B = Intersect(c, b)
d = OrthogonalLine(B, b)
e = OrthogonalLine(A, b)
C = Intersect(f, d, (1.4226497308103743, 0.8246105247997328))
D = Intersect(f, e, (2.5773502691896257, -1.799697312592952))