单位圆与六种三角函数
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①本范例通过动态演示单位圆,展示角度θ与三角函数值(正弦、余弦、正切等)的几何关系;②涉及核心数学概念包括单位圆、三角函数定义、直角三角形边长关系;③作图要点:使用Point, Line, Circle, Tangent, Slider等命令绘制单位圆、坐标轴、三角函数线段,并动态关联θ与函数值;④适合高中数学教学,用于直观理解三角函数定义与性质。
GeoGebra 命令及参数
Point(xAxis) → BPoint(yAxis) → CPoint(yAxis) → DLine(D, C) → YaxisLine(D, B) → XaxisOrthogonalLine(A, Xaxis) → XequalsCosine_1Intersect(Xaxis, XequalsCosine_1) → XequalsCosineCircle(D, B) → UnitCircleTangent(A, UnitCircle) → TangentToA,Intersect(Yaxis, TangentToA) → YequalsCosecantIntersect(Xaxis, TangentToA) → XequalsSecantSegment(D, A) → fSegment(D, XequalsCosine) → CosineθSegment(XequalsCosine, A) → SineθSegment(A, XequalsSecant) → TangentθSegment(A, YequalsCosecant) → CotangentθSegment(D, YequalsCosecant) → CosecantθSegment(D, XequalsSecant) → SecantθOrthogonalLine(A, Sineθ) → YequalsSinePoint(YequalsSine) → HOrthogonalLine(yequalsx, xAxis) → xequalsθIntersect(YequalsSine, xequalsθ) → DerivedSineIntersect(TangentToA, yAxis) → YequalsCosecant2OrthogonalLine(YequalsCosecant2, yAxis) → YequalsCosecant_1Intersect(xequalsθ, YequalsCosecant_1) → DerivedCosecantOrthogonalLine(yequalsx, xequalsθ) → yequalsθIntersect(XequalsCosine_1, yequalsθ) → SidewaysCosineIntersect(f, Cosineθ) → LLine(L, yequalsx) → YequalsXOrthogonalLine(SidewaysCosine, YequalsX) → ReflectsSidewaysCosineIntersect(xequalsθ, ReflectsSidewaysCosine) → DerivedCosineOrthogonalLine(XequalsSecant, yequalsθ) → XequalsSecant_1Intersect(yequalsθ, XequalsSecant_1) → SidewaysSecantOrthogonalLine(SidewaysSecant, YequalsX) → ReflectsSidewaysSecantIntersect(xequalsθ, ReflectsSidewaysSecant) → DerivedSecantOrthogonalLine(B, Secantθ) → Xequals1Line(D, A) → aIntersect(Xequals1, a) → YequalsTangentOrthogonalLine(YequalsTangent, Xequals1) → YequalsTangent_1Intersect(xequalsθ, YequalsTangent_1) → DerivedTangentOrthogonalLine(C, Cosecantθ) → Yequals1Intersect(a, Yequals1) → XequalsCotangent_1OrthogonalLine(XequalsCotangent_1, Yequals1) → XequalsCotangentIntersect(yequalsθ, XequalsCotangent) → SidewaysCotangentOrthogonalLine(SidewaysCotangent, YequalsX) → ReflectsSidewaysCotangentIntersect(xequalsθ, ReflectsSidewaysCotangent) → DerivedCotangent