半圆截面体积计算演示

半圆截面体积计算演示
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2016-03-18 03:09
①本范例演示以已知底面为基础、半圆截面为横截面的体积计算;②涉及核心数学概念包括微积分中的积分计算、函数图像、几何作图等;③构造过程中运用了Segment(线段)、Integral(积分)、Semicircle(半圆)、Sequence(数列)等GeoGebra命令与对象;④适合高中及以上学生及微积分学习者用于理解体积计算与几何模型构建。

GeoGebra 命令及参数

  1. Segment(A, B) → e
  2. Integral((π / 2 * r(x)^(2)), -2, 2) → Integ
  3. If(togDF ≟ 1, "Show Instructions", "Show volume integral") → ToggleDirectionVolumeIntegral
  4. If(togS ≟ 1, "Hide surface", "Show surface") → ShowSurface
  5. Plane((0, 0, 0), (0, 1, 1), (0, 2, 0)) → a
  6. Surface(u, (v * f(u)) + ((1 - v) * g(u)), 0, u, -2, 2, v, 0, 1) → Base
  7. Semicircle(A, B, a) → SC
  8. Sequence(Surface[u, c(-2 + ((k + p) * h)) + (r(-2 + ((k + p) * h)) * cos(β)), (r(-2 + ((k + p) * h)) * sin(β)), u, -2 + (h * k), -2 + ((k + 1) * h), β, 0, π], k, 0, m - 1) → SlicesTop
  9. Sequence(Semicircle[(-2 + (k * h), g(-2 + ((k + p) * h)), 0), (-2 + (k * h), f(-1 + ((k + p) * h)), 0), a], k, 0, m - 1) → SlicesLeft
  10. Sequence(Semicircle[(-2 + ((k + 1) * h), g(-2 + ((k + p) * h)), 0), (-2 + ((k + 1) * h), f(-1 + ((k + p) * h)), 0), a], k, 0, m - 1) → SlicesRight
  11. Sum(Sequence[((h * π / 8) * (g(-2 + ((k + p) * h)) - f(-2 + ((k + p) * h)))^(2)), k, 0, m - 1]) → VolSlices
  12. Sequence(Polygon[(-2 + (k * h), f(-2 + ((k + p) * h))), (-2 + (k * h), g(-2 + ((k + p) * h))), (-2 + ((k + 1) * h), g(-2 + ((k + p) * h))), (-2 + ((k + 1) * h), f(-2 + ((k + p) * h)))], k, 0, m - 1) → SlicesBase
  13. Surface(u, c(u) + (r(u) * cos(β)), (r(u) * sin(β)), u, 0, 2, β, 0, π) → TopRight
  14. Surface(u, c(u) + (r(u) * cos(β)), (r(u) * sin(β)), u, -2, 0, β, 0, π) → TopLeft