螺旋线的构造

螺旋线的构造
几何画板及绘图内容加载中,请稍等……
2020-07-13 21:52
这个范例演示了螺旋线的构造过程。它涉及三维向量和参数方程的核心数学概念。通过使用CurveCartesian, Surface, Segment, Midpoint, Translate, Sequence等GeoGebra命令,可以构建出螺旋线。适合高中数学教学和学习三维几何。

GeoGebra 命令及参数

  1. CurveCartesian((-If[k ≤ 0.5, (((k * 2) * π) * r), (π * r)]) + If[t ≤ ((k * 2) * π), (t * r), (((k * 2) * π) * r) + (r * sin(t - ((k * 2) * π)))], (-r) + If[t ≤ ((k * 2) * π), 0, r - (r * cos(t - ((k * 2) * π)))], t, 0, (2 * π)) → a
  2. CurveCartesian((-If[k ≤ 0.5, (((k * 2) * π) * r), (π * r)]) + If[t ≤ ((k * 2) * π), (t * r), (((k * 2) * π) * r) + (r * sin(t - ((k * 2) * π)))], (-r) + If[t ≤ ((k * 2) * π), 0, r - (r * cos(t - ((k * 2) * π)))], h, t, 0, (2 * π)) → c
  3. CurveCartesian((-If[k ≤ 0.5, (((k * 2) * π) * r), (π * r)]) + If[t ≤ ((k * 2) * π), (t * r), (((k * 2) * π) * r) + (r * sin(t - ((k * 2) * π)))], (-r) + If[t ≤ ((k * 2) * π), 0, r - (r * cos(t - ((k * 2) * π)))], (h * t / 2 / π), t, 0, (2 * π)) → d
  4. Surface((-If[k ≤ 0.5, (((k * 2) * π) * r), (π * r)]) + If[t ≤ ((k * 2) * π), (t * r), (((k * 2) * π) * r) + (r * sin(t - ((k * 2) * π)))], (-r) + If[t ≤ ((k * 2) * π), 0, r - (r * cos(t - ((k * 2) * π)))], s, t, 0, (2 * π), s, 0, h) → b
  5. Segment(((-If[k ≤ 0.5, (((k * 2) * π) * r), (π * r)]), (-r) + 0, 0), ((-If[k ≤ 0.5, (((k * 2) * π) * r), (π * r)]), (-r) + 0, h)) → f
  6. Segment(((-If[k ≤ 0.5, (((k * 2) * π) * r), (π * r)]) + (((k * 2) * π) * r) + (r * sin((2 * π) - ((k * 2) * π))), (-r) + r - (r * cos((2 * π) - ((k * 2) * π))), 0), ((-If[k ≤ 0.5, (((k * 2) * π) * r), (π * r)]) + (((k * 2) * π) * r) + (r * sin((2 * π) - ((k * 2) * π))), (-r) + r - (r * cos((2 * π) - ((k * 2) * π))), h)) → g
  7. Segment((0, (-r), 0), (0, (-r), h)) → i
  8. Surface((v * c(u)) + ((1 - v) * d(u)), u, 0, (2 * π), v, 0, 1) → l
  9. Surface((v * a(u)) + ((1 - v) * d(u)), u, 0, (2 * π), v, 0, 1) → m
  10. Midpoint(f) → A
  11. Midpoint(g) → B
  12. Midpoint(A, B) → C
  13. Translate(l, Vector[(Expand * Vector[C, C + (0, 0, Expand)])]) → l'
  14. Translate(d, Vector[(Expand * Vector[C, C + (0, 0, Expand)])]) → d'
  15. Translate(d, Vector[((2 * Expand) * Vector[C, C + (0, 0, Expand)])]) → d'_1
  16. Translate(m, Vector[((2 * Expand) * Vector[C, C + (0, 0, Expand)])]) → l'_1
  17. Sequence(Translate[d, Vector[((i * Expand) * Vector[C, C + (0, 0, Expand)])]], i, 0, n) → l1
  18. Sequence(Translate[m, Vector[((i * Expand) * Vector[C, C + (0, 0, Expand)])]], i, 0, n) → l2
  19. Segment((0, 0), (0, 0) + (r, 0, 0)) → j
  20. Segment(O, O + (0, 0, h)) → p

AI 绘图提示语参考

绘制一个螺旋线,螺旋线的半径为 r,高度为 h,螺旋线的参数方程为 x = r * t, y = r * (1 - cos(t)), z = r * (t - sin(t)),其中 t 从 0 到 2π。使用螺旋线作为基础,构建一个螺旋面,螺旋面的参数方程为 x = r * t * cos(u), y = r * t * sin(u), z = r * (t - sin(u)),其中 t 从 0 到 2π,u 从 0 到 h。螺旋线的起点和终点之间绘制两条垂直于螺旋线的线段,螺旋线的中点绘制一个点 C,然后将螺旋面和螺旋线沿 C 点平移,平移距离为 Expand。最后,绘制螺旋线的 n 个等距平移副本。
以上提示语为根据原始绘图命令整理而来,仅供参考。