抛物线中的几何均值闪现

GeoGebra 命令及参数

1. Point(g) → A
2. Point(h) → B
3. Line(A, B) → i
4. Intersect(yAxis, i) → C
5. Circle(B, y(A)) → c
6. Intersect(c, j, 1) → D
7. Intersect(j, xAxis) → E
8. Semicircle(D, E) → d
9. Midpoint(E, D) → F
10. OrthogonalLine(B, j) → k
11. Intersect(d, k, 1) → J
12. Dilate(H, If[0 < a ≤ 1, 1 - a, 0], A) → H'
13. Dilate(E, If[0 < a ≤ 1, 1 - a, 0], B) → E'
14. Segment(H, H') → l
15. Segment(E, E') → m
16. Dilate(A, If[2 < a ≤ 3, 3 - a, 0], D) → A'
17. Vector(A, A') → u
18. Translate(H, u) → H'_1
19. Translate(H', u) → H''
20. Segment(H'_1, H'') → l'
21. Rotate(E, If[3 < a ≤ 5, ((a - 3) * π / 2), π], F) → E'_1
22. CircleArc(F, E, E'_1) → e
23. Dilate(G, If[5 < a ≤ 6, 6 - a, 0], C) → G'
24. Segment(G, G') → n
25. Angle(E, B, J) → α
26. Dilate(J, If[6 < a ≤ 7, 7 - a, 0], B) → J'
27. Segment(J, J') → p
28. Segment(A, B) → q
29. Dilate(G, If[7.5 < a ≤ 8.5, 8.5 - a, 0], J) → G'_1
30. Vector(G, G'_1) → v
31. Translate(G, v) → G'_2
32. Translate(G', v) → G''
33. Segment(G'_2, G'') → n'
34. Rotate(G'_2, If[7.5 < a ≤ 8.5, ((a - 7.5) * π / 2), π / 2], G'_2) → K
35. Rotate(G'', If[7.5 < a ≤ 8.5, ((a - 7.5) * π / 2), π / 2], G'_2) → G'''
36. Segment(K, G''') → n''