拉格朗日乘数法示例7

拉格朗日乘数法示例7
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2020-07-16 01:39
该示例演示了拉格朗日乘数法在优化问题中的应用。核心数学概念包括函数的导数和约束条件下的极值问题。通过使用GeoGebra命令如Point、Vector、Simplify等,构建了优化问题的几何模型。适合高中数学教学和学习微积分优化问题。

GeoGebra 命令及参数

  1. Point(Cu_g) → B
  2. Simplify(Derivative[f, x, 1]) → fx'
  3. Simplify(Derivative[f, y, 1]) → fy'
  4. LeftSide(Cu_g) → g
  5. Simplify(Derivative[g, y, 1]) → gy'
  6. Simplify(Derivative[g, x, 1]) → gx'
  7. Vector(B, B + UnitVector[Vector[B, Df]] / n_v) → u_f
  8. Vector(B, B + UnitVector[Vector[B, Dg]] / n_v) → u_g
  9. Angle(u_g, u_f) → α
  10. LaTeX(f, true) → text8a
  11. LaTeX(Cu_g, true) → text8b
  12. LaTeX(Cu0_y, true) → txtCu0_y
  13. Textfield(f) → InputBox3
  14. Textfield(Cu_g) → InputBox4
  15. Surface(sqrt(cos(t)), (0.8 - cos(t)^(2))^(0.25), u, t, (-π), π, u, -3, 1) → g1
  16. Surface((-sqrt(cos(t))), (0.8 - cos(t)^(2))^(0.25), u, t, (-π), π, u, -3, 1) → g2
  17. Surface(sqrt(cos(t)), (-(0.8 - cos(t)^(2))^(0.25)), u, t, (-π), π, u, -3, 1) → g1a
  18. Surface((-sqrt(cos(t))), (-(0.8 - cos(t)^(2))^(0.25)), u, t, (-π), π, u, -3, 1) → g2a
  19. Textfield(n) → InputBox5
  20. Element(l1, Indexmax1) → Amax1
  21. Element(l1, Indexmin1) → Amin1
  22. Element(l2, Indexmin2) → Amin2
  23. Element(l2, Indexmax2) → Amax2
  24. Element(l1f, Indexmax1) → Amax1_{3D}
  25. Element(l2f, Indexmax2) → Amax2_{3D}
  26. Element(l1f, Indexmin1) → Amin1_{3D}
  27. Element(l2f, Indexmin2) → Amin2_{3D}
  28. TableText(Append["N", 1…Length[l1]], Append["\fgcolor{red}{Cp}", l1], Append["\fgcolor{blue}{f}(\fgcolor{red}{C_p })", l1fa], Append["(\dot{f_x},\dot{f_y})", l1xy'_fa], Append["(\dot{g_x},\dot{g_y})", l1xy'_ga], Append["λ_x", lλ1ax], Append["λ_y", lλ1ay], Append["\widehat{\dot{g}\dot{f}} ", lα1], "c|_") → tTab1
  29. TableText(Append["N", 1…Length[l2]], Append["\fgcolor{red}{Cp}", l2], Append["\fgcolor{blue}{f}(\fgcolor{red}{C_p })", l2fa], Append["(\dot{f_x},\dot{f_y})", l2xy'_fa], Append["(\dot{g_x},\dot{g_y})", l2xy'_ga], Append["λ_x", lλ2ax], Append["λ_y", lλ2ay], Append["\widehat{\dot{g}\dot{f}} ", lα2], "c|_") → tTab2
  30. Element(l1f, 5) → Amax15_{3D}
  31. Element(l1, 5) → Amax51
  32. Element(l1, 7) → Amin17
  33. Element(l1f, 7) → Amin17_{3D}
  34. Text("∇f", Point[u_f, 1]) → text25f
  35. Text("∇g", Point[u_g, 1]) → text25g
  36. RotateText(text14, 90°) → text15
  37. Segment(B, C) → f_1
  38. Sequence((0, 0, ((5 * 10^(-6)) * k / n_z)), k, 1, n_z) → lz_n
  39. RemoveUndefined(Zip[Vector[c, c + UnitVector[a] / n_v], a, l1xy'_g, c, l1]) → lvec1_g
  40. RemoveUndefined(Zip[Vector[c, c + UnitVector[a] / n_v], a, l1xy'_f, c, l1]) → lvec1_f
  41. RemoveUndefined(Zip[Vector[c, c + UnitVector[a] / n_v], a, l2xy'_f, c, l2]) → lvec2_f
  42. RemoveUndefined(Zip[Vector[c, c + UnitVector[a] / n_v], a, l2xy'_g, c, l2]) → lvec2_g
  43. Simplify(fx'(x, y) - (gx'(x, y) * fy'(x, y) / gy'(x, y))) → Cu_xf
  44. Simplify(fy'(x, y) - (gy'(x, y) * fx'(x, y) / gx'(x, y))) → Cu_yf
  45. Textfield(txtCu01_x) → InputBox1
  46. Textfield(txtCu01_y) → InputBox2
  47. Zip(Segment[a, b], a, l1, b, l1f) → l1seg
  48. Sequence(Text[i, l1(i) - (0.2, 0.1)], i, 1, lä1) → l1txt
  49. Sequence(Text[i, l2(i) - (0.2, 0.1)], i, 1, lä2) → l2txt
  50. Zip(Segment[a, b], a, l2, b, l2f) → l2seg
  51. Sequence(Translate[Cu_g, Vector[lz_n(k)]], k, 1, 10) → lz_c

AI 绘图提示语参考

绘制一个三维曲面,展示拉格朗日乘数法在优化问题中的应用。曲面上标出几个关键点,并画出该点的梯度向量和约束条件的梯度向量,两者之间的夹角用箭头表示。同时,在曲面上标注出函数的极值点,并用不同颜色区分。最后,在图形旁边用文本框列出计算过程中的关键方程和参数。
以上提示语为根据原始绘图命令整理而来,仅供参考。