平行线与垂直线方程
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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
DynamicCoordinates(C', (round(x(C') / 0.5) * 0.5), (round(y(C') / 0.5) * 0.5)) → PDynamicCoordinates(B', (round(x(B') / 0.5) * 0.5), (round(y(B') / 0.5) * 0.5)) → BDynamicCoordinates(A', (round(x(A') / 0.5) * 0.5), (round(y(A') / 0.5) * 0.5)) → ALine(B, A) → L_1OrthogonalLine(P, L_1) → L_3GCD({Numerator[x(L_3)], Numerator[y(L_3)], Numerator[z(L_3)]}) → hcf3LCM({Denominator[x(L_3)], Denominator[y(L_3)], Denominator[z(L_3)]}) → lcm3Line(P, L_1) → L_2Midpoint(A, B) → MSlope(L_3) → m_3If(m_3^(2) ≠ 1, FractionText[m_3], If[m_3 ≟ -1, "-", ""]) → textm3Angle(L_1, L_3) → αSlope(L_2) → m_2GCD({Numerator[x(L_2)], Numerator[y(L_2)], Numerator[z(L_2)]}) → hcf2LCM({Denominator[x(L_2)], Denominator[y(L_2)], Denominator[z(L_2)]}) → lcm2If(m_2^(2) ≠ 1, FractionText[m_2], If[m_2 ≟ -1, "-", ""]) → textm2Segment(M, A) → fSegment(M, B) → gGCD({Numerator[x(L_1)], Numerator[y(L_1)], Numerator[z(L_1)]}) → hcf1LCM({Denominator[x(L_1)], Denominator[y(L_1)], Denominator[z(L_1)]}) → lcm1Slope(L_1) → m_1