动画演示几何变换与优化问题 by Tim Brzezinski

动画演示几何变换与优化问题 by Tim Brzezinski
几何画板及绘图内容加载中,请稍等……
2017-03-02 19:20
①本范例通过动画演示三角形与圆的几何变换,结合函数图像分析角度与最值问题;②涉及核心概念:几何变换(缩放、旋转)、解析几何、函数最值、优化问题;③构造要点:使用Line, Point, Circle, Dilate, Segment, Intersect, Polygon等命令创建几何对象,并通过Dilate实现变换,Intersect求交点;④适合高中及以上学生,用于理解几何变换、函数优化及解析几何应用。

GeoGebra 命令及参数

  1. Line(A_1, A') → f
  2. Line(A_1, C') → g
  3. Line(A_1, B') → h
  4. Point(g) → C
  5. Point(g) → C'_1
  6. Point(f) → A'_1
  7. Point(f) → A
  8. Point(h) → B
  9. Point(h) → B'_1
  10. Circle(A'_1, 1) → r
  11. Circle(A, 1) → t
  12. Dilate(A_1, If[0 < a ≤ 1, 1 - a, 0], A) → N
  13. Dilate(A_1, If[0 < a ≤ 1, 1 - a, 0], A') → O
  14. Segment(A_1, N) → b
  15. Segment(A_1, O) → i_1
  16. Dilate(A_1, If[1 < a ≤ 2, 2 - a, 0], B') → P
  17. Dilate(A_1, If[1 < a ≤ 2, 2 - a, 0], B) → Q
  18. Segment(A_1, P) → l_1
  19. Segment(A_1, Q) → m_1
  20. Dilate(A_1, If[2 < a ≤ 3, 3 - a, 0], C') → H
  21. Dilate(A_1, If[2 < a ≤ 3, 3 - a, 0], C) → I
  22. Segment(A_1, H) → c
  23. Segment(A_1, I) → d
  24. Line(A', B') → j
  25. Line(B, A) → k
  26. Intersect(j, k) → D
  27. Line(C', B') → l
  28. Line(B, C) → m
  29. Intersect(l, m) → E
  30. Line(C', A') → n
  31. Line(A, C) → p
  32. Intersect(n, p) → F
  33. Polygon(A, C, B) → poly1, b_1, a_1, c_1
  34. Polygon(A', B', C') → poly3, c', a', b'
  35. Dilate(B, If[5 < a ≤ 6, 6 - a, 0], D) → B'_2
  36. Segment(B, B'_2) → i
  37. Dilate(A', If[5 < a ≤ 6, 6 - a, 0], D) → A''
  38. Segment(A', A'') → q
  39. Dilate(B, If[6 < a ≤ 7, 7 - a, 0], E) → B'_3
  40. Dilate(C', If[6 < a ≤ 7, 7 - a, 0], E) → C''
  41. Segment(B, B'_3) → s
  42. Segment(C', C'') → e
  43. Dilate(A, If[7 < a ≤ 8, 8 - a, 0], F) → A'_2
  44. Dilate(C', If[7 < a ≤ 8, 8 - a, 0], F) → C''_1
  45. Segment(C', C''_1) → f_1
  46. Segment(A, A'_2) → g_1
  47. Dilate(D, If[10 < a ≤ 11, 11 - a, 0], E) → D'
  48. Dilate(E, If[11 < a ≤ 12, 12 - a, 0], F) → E'
  49. Segment(D, D') → h_1
  50. Segment(E, E') → j_1