探索立方体截面

探索立方体截面
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2018-10-29 16:36
①本范例演示通过不同角度切割立方体,观察其截面形状的变化;②涉及核心数学概念包括立体几何、截面几何、二次函数、对数函数及极限;③作图要点运用了GeoGebra命令如Cube(立方体)、Polygon(多边形)、PointIn(点在路径上)、Translate(平移)、Rotate(旋转)、Point(点)、Plane(平面)、IntersectPath(路径相交)、OrthogonalLine(垂线);④适合高中及以上学生及数学爱好者用于理解空间几何与函数应用。

GeoGebra 命令及参数

  1. Cube((-1.5, -1.5, 0), (1.5, -1.5, 0), xOyPlane) → m, M, face4, face5, face6, edge1, edge2, edge3, edge4, edge5, edge6, edge7, N, edge8, edge9, edge10, edge11, edge12, Q, R, S, T, face1, face2, face3
  2. Polygon(B + (-2, -2), B + (2, -2), B + (2, 2), B + (-2, 2)) → poly3, e, f, g, i
  3. PointIn(poly3) → C
  4. Translate((0, 0, 0), Vector[B, C]) → A
  5. Polygon(A + (-4, -4), A + (4, -4), A + (4, 4), A + (-4, 4)) → poly1, a, b, c, d
  6. Rotate(Rotate[Translate[poly1, Vector[A, A + (0, 0, h)]], (90° * s), A + (0, 0, h), yAxis], (90° * t), A, zAxis) → poly2
  7. Rotate(D, 120°, (0, 0, 0)) → E
  8. Polygon(D, E, 3, xOyPlane) → poly4, j, k, l, F
  9. Point(list1) → G
  10. Point(list2) → H
  11. Point(list3) → I
  12. Plane(G, I, H) → n
  13. IntersectPath(n, m) → poly6, poly5, V, p, q, r, a_1, b_1, c_1, e_1, f_1, poly7, K, L_1, O, P, J, L, U
  14. Rotate(m, 0, zAxis) → m'
  15. Rotate(m, 0, zAxis) → m'_1
  16. OrthogonalLine(A, n) → d_1