抛物线：形成与效应

GeoGebra 命令及参数

1. IntersectPath(c, a) → d
2. Line((0, 0, 0), (1, 0, 1)) → f
3. Line(A, f) → g
4. Distance(A, (0, 0, 0)) → e
5. Sphere(A, (0.4 * e)) → h
6. IntersectPath(y = 0, h) → k
7. Intersect(g, k) → B, C
8. Intersect(xAxis, k) → D, E
9. Rotate(D, If[0 < i ≤ 1, ((-i) * π / 4), ((-π)) / 4], A, Line[(4, 0, 0), (4, 1, 0)]) → D'
10. CircleSector(A, D, D') → p
11. Dilate(A, If[1.5 < i ≤ 2.5, 2.5 - i, 0], (0, 0, 0)) → A'
12. Vector(A, A') → u
13. Translate(p, u) → p'
14. Line(A, (x(A), y(A) + 1, 0)) → l
15. Rotate(j, ((-m) * π / 180), l) → j'
16. IntersectPath(j', a) → q
17. Line((100, 0, 0), A) → n
18. Focus(q) → F, G
19. Point(q) → H
20. Vertex(q) → I, , ,
21. Sphere(I, F) → c_1
22. Intersect(g, c_1) → J, K
23. Sphere(K, I) → e_1
24. Intersect(g, e_1) → L, M
25. LineBisector(L, K, Plane[H, F, K]) → f_1
26. Intersect(g, f_1) → N
27. Dilate(F, If[4 < i ≤ 5, 5 - i, 0], H) → F'
28. Segment(F, F') → g_1
29. Line(H, g) → h_1
30. Intersect(f_1, h_1) → O
31. Intersect(f_1, g) → P
32. Angle(F, H, O) → β
33. Rotate(F, If[5 < i ≤ 6, ((-(i - 5)) * β), (-β)], H, Plane[F, H, P]) → F'_1
34. Rotate(F', If[5 < i ≤ 6, ((-(i - 5)) * β), (-β)], H, Plane[F, H, P]) → F''
35. Segment(F'_1, F'') → i_1
36. Vector(P, K) → u_1
37. Translate(f_1, u_1) → j_1
38. Intersect(j_1, h_1) → Q
39. Angle(H, Q, K) → α