Ha 2016

a = 4
b = 2
c = 2.5 (slider from -5 to 5, step 1)
d = 3 (slider from -5 to 5, step 1)
e: x^(2) / a^(2) + y^(2) / b^(2) = 1
f: x^(2) / c^(2) + y^(2) / d^(2) = 1
H(x, y) = ((x^(2) / a^(2) + y^(2) / b^(2) - 1) * (x^(2) / c^(2) + y^(2) / d^(2) - 1))
h = 0.009 (slider from -5 to 5, step 0.01)
g(x, y) = H(x, y) + h
i: H(x, y) - h = 0
A, B, C, D = Intersect(e, f)
a_k = -1.4 (slider from -5 to 5, step 0.1)
b_k = -0.4 (slider from -5 to 5, step 0.01)
k: (x - x(B))^(2) / a_k^(2) + (y - y(B))^(2) / b_k^(2) = 1
j: H(x, y) - (h * ((x - x(B))^(2) / a_k^(2) + (y - y(B))^(2) / b_k^(2) - 1)) = 0
p: (x - x(B))^(2) / a_k^(2) + (y - y(B))^(2) / b_k^(2) = 1