椭圆滚动

椭圆滚动
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2015-09-10 07:16
①本范例演示椭圆在直线上滚动时,其上一点的轨迹;②涉及核心数学概念包括椭圆、周长、全等、条形图、箱线图、组合数学;③作图要点:使用了Point, Segment, Midpoint, OrthogonalLine, Circle, Center, Intersect, Ellipse, Arc, Tangent, Angle, Rotate, Ray, Mirror等GeoGebra命令和对象;④适合高中阶段学习解析几何和几何变换的学生使用。

GeoGebra 命令及参数

  1. Point(Circle[A, (2 * a)]) → B
  2. Segment(A, B) → c
  3. Midpoint(A, B) → C
  4. OrthogonalLine(C, c) → d
  5. Circle(C, b) → e
  6. Center(e) → D
  7. Intersect(e, d) → E, F
  8. Circle(F, Segment[A, C]) → f
  9. Intersect(f, c) → G, H
  10. Ellipse(G, H, F) → g
  11. Point(g) → I
  12. Arc(g, A, I) → arc
  13. Point(Circle[J, Circumference[g]]) → K
  14. Segment(J, K) → h
  15. Circle(J, arc) → k
  16. Intersect(k, h, 1) → L
  17. Segment(J, L) → i
  18. Segment(G, I) → j
  19. Tangent(I, g) → l,
  20. Point(l) → M
  21. Angle(G, I, M) → α
  22. Rotate(J, (-α), L) → J'
  23. Angle(J', L, J) → β
  24. Ray(L, J') → m
  25. Circle(L, Segment[G, I]) → p
  26. Intersect(p, m, 1) → N
  27. Mirror(N, h) → N'
  28. Ray(N', L) → n
  29. Circle(N', (2 * a)) → q
  30. Intersect(q, n, 1) → O
  31. Ellipse(N, O, L) → r
  32. Circle(J, Segment[A, B]) → t