橢圓的包絡線
Author: 藍邦偉  老師

橢圓的包絡線

$ B $

$ A $

$間隔%v$

$ P $

u = Vector((x(Corner[1]), 0), (x(Corner[3]), 0))
v = Vector((0, y(Corner[1])), (0, y(Corner[3])))
A = Point(u)
B = Point(u)
r = 3.9999999999999996 (slider from 1 to 10, step 0.1)
C = Circle(B, r)
M: 0.5 * (A + B)
c = Segment(M, A)
d: (x - x(M))^(2) / (r / 2)^(2) + (y - y(M))^(2) / ((r / 2)^(2) - c^(2)) = 1
t = 0 rad (slider from 0*° to 6.283185307179586, step h°)
P: (x(M) + r / 2 * cos(t), y(M) + sqrt((r / 2)^(2) - c^(2)) * sin(t))
b, f = Tangent(P, d)
D, E = Intersect(C, b)
e = Segment(D, E)
Q_2: 0.2 * Corner[2] + 0.8 * Corner[1]
Q_3: (x(Q_2), y(Corner[3]))
poly1, a, q_2, q_3, g = Polygon(Corner[1], Q_2, Q_3, Corner[4])
h = 1 (slider from 0.1 to 2, step 0.1)