利用圆盘法计算旋转体体积

利用圆盘法计算旋转体体积
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2016-03-20 09:44
①本范例演示了如何利用圆盘法计算旋转体的体积;②涉及的核心数学概念包括积分、函数图像、旋转体体积计算;③作图要点——从下方『构造摘要』提炼用到了哪些 GeoGebra 命令/对象:Intersect(求交点)、Sequence(序列)、Sum(求和)、Polygon(多边形)、Rotate(旋转)、Integral(积分)、Surface(曲面)、RectangleSum(矩形和);④适合的学段或用途:高中及以上数学教学,用于理解和应用积分在体积计算中的实际应用。

GeoGebra 命令及参数

  1. Intersect(g, f, 0, 2) → A, B
  2. Sequence(Cylinder[(a + (k * h), 1, 0), (a + ((k + 1) * h), 1, 0), 1 + f(a + ((k + p) * h))], k, 0, m - 1) → CO
  3. Sequence(Cylinder[(a + (k * h), 1, 0), (a + ((k + 1) * h), 1, 0), 1 + g(a + ((k + p) * h))], k, 0, m - 1) → CI
  4. Sequence(Polygon[(a + (k * h), f(a + ((k + p) * h))), (a + ((k + 1) * h), f(a + ((k + p) * h))), (a + ((k + 1) * h), g(a + ((k + p) * h))), (a + (k * h), g(a + ((k + p) * h)))], k, 0, m - 1) → Rectangles
  5. Sequence(If[Defined[Volume[Element[CO, k]]], Volume[Element[CO, k]], 0], k, 1, m) → VCO
  6. Sequence(If[Defined[Volume[Element[CI, k]]], Volume[Element[CI, k]], 0], k, 1, m) → VCI
  7. Sum(VCO - VCI) → VC
  8. Polygon((a + (DK * h), g(a + ((DK + p) * h))), (a + ((DK + 1) * h), g(a + ((DK + p) * h))), (a + ((DK + 1) * h), f(a + ((DK + p) * h))), (a + (DK * h), f(a + ((DK + p) * h)))) → Rectangle1, c, d, e, k
  9. Rotate(Rectangle1, (-α), line) → Rectangle1'
  10. Integral((π * ((g(x) - 1)^(2) - (f(x) - 1)^(2))), a, b) → VolInteg
  11. Rotate(f_1, (-α), line) → i
  12. Rotate(g_1, (-α), line) → j
  13. Rotate(Rectangles, (-α), line) → Rectangles'
  14. Surface(u, 1 + ((f(u) - 1) * cos(β)), ((f(u) - 1) * sin(β)), u, a, b, β, 0, (2 * π)) → Inner
  15. Surface(a + (DK * h), 1 + ((u - 1) * cos(β)), ((u - 1) * sin(β)), u, f(a + ((DK + p) * h)), g(a + ((DK + p) * h)), β, 0, α) → SideLeft1
  16. Surface(a + ((DK + 1) * h), 1 + ((u - 1) * cos(β)), ((u - 1) * sin(β)), u, f(a + ((DK + p) * h)), g(a + ((DK + p) * h)), β, 0, α) → SideRight1
  17. Surface(u, 1 + ((g(u) - 1) * cos(β)), ((g(u) - 1) * sin(β)), u, a, b, β, 0, (2 * π)) → Outer
  18. Surface(u, 1 + ((f(a + ((DK + p) * h)) - 1) * cos(β)), ((f(a + ((DK + p) * h)) - 1) * sin(β)), u, a + (DK * h), a + ((DK + 1) * h), β, 0, α) → Inner1
  19. Surface(u, 1 + ((g(a + ((DK + p) * h)) - 1) * cos(β)), ((g(a + ((DK + p) * h)) - 1) * sin(β)), u, a + (DK * h), a + ((DK + 1) * h), β, 0, α) → Outer1
  20. Sequence(Surface[u, 1 + ((g(a + ((k + p) * h)) - 1) * cos(β)), ((g(a + ((k + p) * h)) - 1) * sin(β)), u, a + (k * h), a + ((k + 1) * h), β, 0, α], k, 0, m - 1) → Inners
  21. Sequence(Surface[u, 1 + ((f(a + ((k + p) * h)) - 1) * cos(β)), ((f(a + ((k + p) * h)) - 1) * sin(β)), u, a + (k * h), a + ((k + 1) * h), β, 0, α], k, 0, m - 1) → Outers
  22. Sequence(Surface[a + (k * h), 1 + ((u - 1) * cos(β)), ((u - 1) * sin(β)), u, f(a + ((k + p) * h)), g(a + ((k + p) * h)), β, 0, α], k, 0, m - 1) → SidesLeft
  23. Sequence(Surface[a + ((k + 1) * h), 1 + ((u - 1) * cos(β)), ((u - 1) * sin(β)), u, f(a + ((k + p) * h)), g(a + ((k + p) * h)), β, 0, α], k, 0, m - 1) → SidesRight
  24. RectangleSum((π * ((ℯ^((2 * x) - x^(2)) - 1)^(2) - 1)), a, a + (m * h), m, p) → VCyls

AI 绘图提示语参考

绘制一个三维旋转体,展示垫片法求体积。在坐标系中,两条函数曲线围成一个区域,该区域绕水平轴旋转形成内外两个曲面,中间有多个薄圆柱垫片。图形包含:外曲面、内曲面、若干半透明垫片、一个高亮矩形截面及其旋转后的位置,以及一条积分曲线。构造顺序:先画出两条函数曲线并标记交点,再生成一系列圆柱垫片,然后绘制旋转后的矩形和曲面,最后显示体积积分公式。整体呈现半透明效果,便于观察内部结构。
以上提示语为根据原始绘图命令整理而来,仅供参考。