椭圆的反射性质 by Tim Brzezinski (2)

GeoGebra 命令及参数

1. Ellipse(A, B, C) → c
2. Point(c) → P
3. Tangent(P, c) → a,
4. Segment(A, P) → b
5. Segment(B, P) → d
6. Circle(P, 1) → e
7. Intersect(e, b, 1) → E
8. Intersect(e, a) → F, G
9. Intersect(e, d, 1) → H
10. Angle(F, P, E) → α
11. Angle(H, P, G) → β
12. CircleSector(P, F, E) → f
13. Rotate(f, (g * γ), P) → f'
14. CircleSector(P, F, H) → k
15. Dilate(A, If[-2 < g ≤ -1, -1 - g, 0], P) → A'
16. Segment(A, A') → i
17. Dilate(B, If[-1 < g ≤ 0, (-g), 0], P) → B'
18. Segment(B, B') → j
19. Rotate(F, If[-1 < g ≤ 0, ((g + 1) * α), α], P) → F'
20. CircleSector(P, F, F') → q
21. Rotate(q, If[0.5 < g ≤ 1.5, ((g - 0.5) * (π - α)), π - α], P) → q'
22. Intersect(e, a, 2) → D
23. Intersect(α, a, 1) → I
24. Point(a) → J
25. Angle(J, P, B) → ε
26. Intersect(e, i) → K,
27. Rotate(D, If[-1 < g ≤ 0, ((-(g + 1)) * ε), (-ε)], P) → D'
28. CircleSector(P, D', D) → r
29. Rotate(r, If[0.5 < g ≤ 1.5, ((-(g - 0.5)) * (π - ε)), ε - π], P) → r'