二元一次方程未知数求解与图像绘制互动练习

二元一次方程未知数求解与图像绘制互动练习
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2016-06-06 02:21
① 本范例通过交互式界面展示二元一次方程中未知数的求解过程,并同步绘制对应的直线图像,帮助学生直观理解方程与图像的关系。② 核心数学概念包括二元一次方程、线性函数、斜率与截距、坐标平面上的直线表示,以及通过代入法或消元法求解未知数。③ 作图要点:利用GeoGebra的文本输入框(InputBox1)接收用户答案,通过TextToUnicode、Length、If、Sum等命令解析输入并判断正确性;使用RandomElement随机生成题目参数,Simplify和Sequence处理表达式,TableText生成数值表格,Point和Vector构造坐标点与向量,最终绘制直线并显示交点。④ 适合初中至高中阶段学生作为课堂练习或课后复习,也可用于教师演示线性方程求解与图像绘制的结合。

GeoGebra 命令及参数

  1. TextToUnicode(usertxtanswerq) → listdigitsq
  2. Length(listdigitsq) → lengthlistdigitsq
  3. If(Element[listdigitsq, 1] ≟ 45, 2, 1) → startindexq
  4. Sum((If[Element[listdigitsq, 1] ≟ 45, -1, 1] * Sequence[((Element[listdigitsq, i] - 48) * 10^(lengthlistdigitsq - i)), i, startindexq, lengthlistdigitsq])) → useranswerqnum
  5. TextToUnicode(usertxtanswerp) → listdigitsp
  6. If(Element[listdigitsp, 1] ≟ 45, 2, 1) → startindexp
  7. Length(listdigitsp) → lengthlistdigitsp
  8. Sum((If[Element[listdigitsp, 1] ≟ 45, -1, 1] * Sequence[((Element[listdigitsp, i] - 48) * 10^(lengthlistdigitsp - i)), i, startindexp, lengthlistdigitsp])) → useranswerpnum
  9. RandomElement({-1, 1, 2, -2, -3, 3, 4, -4, -1, 1, -2, 2, 5, -5, -1, 1}) → a_1
  10. RandomElement({0, -1, 1, 2, -2, -3, 3, 0, -1, 1, -2, 2, 4, -4, 0, -1, 1, -2, 2, 5, -5, 0, -1, 1, -2, 2}) → n_3
  11. RandomElement({-1, 0, 1, 2, -2, 0, -3, 3}) → x_g
  12. RandomElement({-1, 1, 2, -2, -3, 3, 4, -4, -1, 1, -2, 2, 5, -5, -1, 1}) → b_1
  13. Simplify(If[-10 ≤ x ≤ 10, ((-(x(e_n) / y(e_n))) * x) - z(e_n) / y(e_n)]) → f
  14. Sequence(abs(f(0) - (a_1 / b_1 * i) - round(f(0) - (a_1 / b_1 * i), 0)), i, 0, abs(b_1 - 1)) → listsearch1stinteger, {0, 0, 0}
  15. Sort(Sequence[xInty + (b_1 * i), i, -2, 2, 1]) → listxno
  16. RandomElement({1, 2, 3, 4}) → shiftposty
  17. Join({{x}, listxno}) → listx
  18. RandomElement(Remove[{1, 2, 3, 4}, {shiftposty}]) → shiftpostx
  19. Remove(listx, {Element[listx, shiftpostx + 1]}) → listprex
  20. Join({{y}, (m * listxno) + d}) → listy
  21. Remove(listy, {Element[listy, shiftposty + 1]}) → listprey
  22. Insert("p", listprey, shiftposty + 1) → listypost
  23. Element(listy, shiftposty + 1) → answerp
  24. Element(listx, shiftposty + 1) → x_p
  25. GCD({a_1, b_1, c_1}) → c_g
  26. Insert("q", listprex, shiftpostx + 1) → listxpost
  27. TableText({listxpost, listypost}, "c_|h") → txtTableValues
  28. Element(listy, shiftpostx + 1) → y_q
  29. Textfield(usertxtanswerp) → InputBox1
  30. Textfield(usertxtanswerq) → InputBox2
  31. If(useranswerpnum ≟ Element[listy, shiftposty + 1], true, false) → answerpcorrect
  32. If(useranswerqnum ≟ Element[listx, shiftpostx + 1], true, false) → answerqcorrect
  33. Element(listx, shiftpostx + 1) → answerq
  34. CoordPointertoAxes6(P) → A, B, text2, text3, text4, text5, text6, u, v
  35. CoordPointertoAxes6(Q) → C, D, text7, text8, text9, text10, text11, w, a
  36. IndexOf("p", listypost) → indexofp
  37. IndexOf("q", listxpost) → indexofq
  38. Sequence((Element[listxno, i], Element[listyno, i]), i, 1, 5) → listallpoints
  39. Point(Circle[P_{useranswerq}, x(P_{useranswerq})]) → E_o
  40. Vector(P_{useranswerq}, (x(P_{useranswerq}), 0)) → g
  41. Vector(P_{useranswerp}, (0, y(P_{useranswerp}))) → b
  42. Min(Min[listxno] - ((Max[listxno] - Min[listxno]) * 0.2), Min[-2, If[Defined[useranswerqnum], useranswerqnum - 1, 0]]) → xMin
  43. Max(Max[listxno] + ((Max[listxno] - Min[listxno]) * 0.1), Max[2, If[Defined[useranswerqnum], useranswerqnum - 1, 0]]) → xMax
  44. Max(Max[listyno] + ((Max[listyno] - Min[listyno]) * 0.1), Max[2, If[Defined[useranswerpnum], useranswerpnum + 1, 0]]) → yMax
  45. Min(Min[listyno] - ((Max[listyno] - Min[listyno]) * 0.1), Min[-2, If[Defined[useranswerpnum], useranswerpnum - 1, 0]]) → yMin
  46. Point(e_n) → E
  47. Vector(E, (x(E), 0)) → c
  48. Vector(E, (0, y(E))) → e