g(x)=4\sin(x)

h(x)=\cos(x)

f(x)=\cos(4\sin(x))

k = 4 (slider from 0 to 5, step 0.1)
g(x) = (k * sin(x))
h(x) = cos(x)
f(x) = h(g(x))
A = Point(xAxis)
i = OrthogonalLine(A, xAxis)
B: (x(A) + k, 0)
p: y = x
j = OrthogonalLine(B, yAxis)
O = Intersect(p, j)
l = OrthogonalLine(O, xAxis)
E': (x(B), f(x(B)))
E = Intersect(g, i, (2.653138926978123, 1.877043993087456))
m = OrthogonalLine(E, l)
F = Intersect(p, m)
n = OrthogonalLine(F, j)
G = Intersect(h, n, (1.877043993087456, -0.3014830238626446))
q = OrthogonalLine(G, i)
P = Intersect(i, q)
I = Intersect(g, yAxis, 1)
v1, h_1, e, f_1, g_1 = Polygon(P, E, F, G)
f'(x) = f'(x)
u = Vector(A, E)
v = Vector(E, F)
w = Vector(F, G)
a = Vector(G, P)
b = Vector(A, P)
C = (0.19449045348897548, 4.116544425524696)
D = (0.8590584658018953, 4.116544425524696)
H = (0.19524976166529745, 5.0409544589333715)