极坐标圆锥曲线演示
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所属专题
Conics Doug Kuhlmann
①本范例通过极坐标方程演示圆锥曲线(椭圆、双曲线、抛物线)的绘制,直观展示离心率与准线的几何意义;②涉及核心数学概念包括极坐标方程、离心率、准线、二次曲线性质;③构造中运用了CurveCartesian绘制曲线、Vector创建向量、If条件判断、Max/Min求极值、Textfield显示文本、SurdText处理根号文本等命令;④适合高中解析几何教学,帮助学生理解圆锥曲线定义与性质,提升数学建模能力。
GeoGebra 命令及参数
CurveCartesian((rc(t) * cos(t)), (rc(t) * sin(t)), t, 0, 6.283185307179586) → rcpVector(rcp(θ)) → uIf(togneg ≟ 0, "+", "-") → tgnIf(togneg ≟ 1, "Change to +", "Change to -") → PlusMinusCurveCartesian((rs(t) * cos(t)), (rs(t) * sin(t)), t, 0, 6.28319) → rspVector(rsp(θ)) → wMax({x(Vc_1), x(Vc_2), x(Vs_1), x(Vs_2)}) → MaxXMin({x(Vc_1), x(Vc_2), x(Vs_1), x(Vs_2)}) → MinXMax({y(Vc_1), y(Vc_2), y(Vs_1), y(Vs_2)}) → MaxYMin({y(Vc_1), y(Vc_2), y(Vs_1), y(Vs_2)}) → MinYIf(sn, x(Cs), x(Cc)) → xCenIf(sn, y(Cs), y(Cc)) → yCenMax(abs(MaxX), abs(MinX)) → MXMax(abs(MaxY), abs(MinY)) → MYTextfield(ecc) → eEQTextfield(dtrx) → dEQMin(abs(y(Vs_1)), abs(y(Vs_2))) → FVsMin(abs(x(Vc_1)), abs(x(Vc_2))) → FVcIf(SIGN < 0, Cs + (0, csi), Cs - (0, csi)) → FsIf(SIGN < 0, Cc + (csi, 0), Cc - (csi, 0)) → FcSurdText(Cc) → CcValueSurdText(Cs) → CsValue