动画143：函数与三维向量演示

GeoGebra 命令及参数

1. Point(x = 0) → A
2. PointIn(a) → B
3. PointIn(b) → C
4. PointIn(c) → D
5. PointIn(d) → E
6. FitPoly(list, 4) → f
7. Mirror(g, x = 0) → g_1
8. Point(g) → F
9. Intersect(h, y = 0) → G
10. Mirror(G, x = 0) → G'
11. Mirror(F, x = 0) → F'
12. Dilate(H, If[0 < e ≤ 1, 1 - e, 0], G) → H'
13. Segment(H, H') → i
14. Dilate(G, If[1 < e ≤ 2, 2 - e, 0], F) → G'_1
15. Segment(G, G'_1) → j
16. Rotate(H, If[2 < e ≤ 3, ((-(e - 2)) * π), (-π)], H) → H'_1
17. Rotate(H', If[2 < e ≤ 3, ((-(e - 2)) * π), (-π)], H) → H''
18. Segment(H'_1, H'') → i'
19. Dilate(G', If[3 < e ≤ 4, 4 - e, 0], F') → G''
20. Segment(G', G'') → k
21. Dilate(F, If[4 < e ≤ 5, 5 - e, 0], F') → F'_1
22. Vector(F, F'_1) → u
23. Translate(G, u) → G'_2
24. Translate(G'_1, u) → I
25. Segment(G'_2, I) → j'