利用截面和函数建模构建曲面
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①本范例演示如何通过指定截面创建三维固体模型;②涉及核心数学概念包括微积分、几何、积分计算、函数建模、三角函数等;③作图要点提炼自构造摘要,使用了Segment(线段)、Midpoint(中点)、Intersect(交点)、Line(直线)、Sphere(球体)、Polygon(多边形)、CurveCartesian(笛卡尔曲线)、Surface(曲面)等GeoGebra命令和对象;④适合高中及以上学生及需要立体几何和微积分实践的数学爱好者。
GeoGebra 命令及参数
Segment(H, I) → s_1Midpoint(s_1) → ESegment(J, K) → q_1Midpoint(q_1) → FIntersect(upper, h, (-2.3, 9.25429478782328)) → BIntersect(lower, h, (-2.3, -4.471)) → CSegment(C, B) → qIntersect(upper, q, (-2.2999999999999994, 9.25429478782328)) → GMidpoint(C, G) → TLine(B, D) → iSphere(B, d) → eSegment(C, B) → pPolygon(C, G, U) → q1, f_1, g_1, n_1Polygon(K, J, W) → q2, l, m, nPolygon(Q, P, V) → q3, r, s, tSegment(K, W) → fSegment(W, J) → gSegment(Q, V) → jSegment(V, P) → kCurveCartesian(t, (0.5 * (upper(t) + lower(t))), ((sqrt(3) * 1 / 2) * (upper(t) - lower(t))), t, a, b) → cSurface(u, ((1 - v) * lower(u)) + ((0.5 * v) * (lower(u) + upper(u))), (sqrt(3) / 2 * (v * (upper(u) - lower(u)))), u, a, b, v, 0, 1) → oSurface(u, (v * upper(u)) + (((1 - v) * 0.5) * (lower(u) + upper(u))), (((sqrt(3) * 0.5) * (1 - v)) * (upper(u) - lower(u))), u, a, b, v, 0, 1) → uSegment(C, U) → i_1Segment(U, G) → j_1Segment(C, G) → k_1