f(x) = 1 + cos(x)
g(x) = sin(x)
h(x) = 2 * sin(x / 2)
a = 0.05 (slider from 0.05 to 1, step 0.05)
list1 = Sequence(Segment[(f(t), g(t), h(t)), (f(t + a), g(t + a), h(t + a))], t, -6.283185307179586, 6.283185307179586, a)
A = Intersect(zAxis3D, yAxis3D)
b = Sphere(A, 2)
f_x = Derivative(f, x)
g_x = Derivative(g, x)
h_x = Derivative(h, x)
t = 1.6168146928204141 (slider from -6.283185307179586 to 6.283185307179586, step 0.1)
P: (f(t), g(t), h(t))
k = 0.44 (slider from 0.01 to 1, step 0.01)
Q: (f(t + k), g(t + k), h(t + k))
u = Vector(A, P)
v = Vector(A, Q)
C: P + (v - u) / k
w = Vector(P, C)