平行线与垂直线方程

平行线与垂直线方程
几何画板及绘图内容加载中,请稍等……
2019-01-09 10:50
本范例演示平行线与垂直线的方程关系。涉及核心数学概念包括平行线的斜率相等、垂直线的斜率乘积为-1。构造要点使用了DynamicCoordinates, Line, OrthogonalLine, GCD, LCM, Midpoint, Slope, If, Angle, Segment等GeoGebra命令与对象。适合高中阶段学习解析几何的学生使用。

GeoGebra 命令及参数

  1. DynamicCoordinates(C', (round(x(C') / 0.5) * 0.5), (round(y(C') / 0.5) * 0.5)) → P
  2. DynamicCoordinates(B', (round(x(B') / 0.5) * 0.5), (round(y(B') / 0.5) * 0.5)) → B
  3. DynamicCoordinates(A', (round(x(A') / 0.5) * 0.5), (round(y(A') / 0.5) * 0.5)) → A
  4. Line(B, A) → L_1
  5. OrthogonalLine(P, L_1) → L_3
  6. GCD({Numerator[x(L_3)], Numerator[y(L_3)], Numerator[z(L_3)]}) → hcf3
  7. LCM({Denominator[x(L_3)], Denominator[y(L_3)], Denominator[z(L_3)]}) → lcm3
  8. Line(P, L_1) → L_2
  9. Midpoint(A, B) → M
  10. Slope(L_3) → m_3
  11. If(m_3^(2) ≠ 1, FractionText[m_3], If[m_3 ≟ -1, "-", ""]) → textm3
  12. Angle(L_1, L_3) → α
  13. Slope(L_2) → m_2
  14. GCD({Numerator[x(L_2)], Numerator[y(L_2)], Numerator[z(L_2)]}) → hcf2
  15. LCM({Denominator[x(L_2)], Denominator[y(L_2)], Denominator[z(L_2)]}) → lcm2
  16. If(m_2^(2) ≠ 1, FractionText[m_2], If[m_2 ≟ -1, "-", ""]) → textm2
  17. Segment(M, A) → f
  18. Segment(M, B) → g
  19. GCD({Numerator[x(L_1)], Numerator[y(L_1)], Numerator[z(L_1)]}) → hcf1
  20. LCM({Denominator[x(L_1)], Denominator[y(L_1)], Denominator[z(L_1)]}) → lcm1
  21. Slope(L_1) → m_1