探索单位圆
几何画板及绘图内容加载中,请稍等……
①本范例演示单位圆及其与特殊直角三角形的联系;②涉及核心数学概念包括单位圆定义、三角函数值、特殊角(30°、45°、60°)的几何表示;③作图要点:使用GeoGebra命令如Point, Sequence, Segment, Min, If, Polygon, Element, Random, Angle等构建单位圆、特殊三角形及角度关系;④适合高中数学教学,用于理解三角函数与几何图形的关联。
GeoGebra 命令及参数
Point(c) → ASequence(((π * k)) / 12, k, 0, 24) → AnglesSequence((cos(Element[Angles306090, k]), sin(Element[Angles306090, k])), k, 1, 9) → Pts306090Segment(O, B) → dMin(abs(Angles306090 - acosd(x(A)))) → d306090Min(abs(Angles459045 - acosd(x(A)))) → d459045Min(abs(AnglesVH - acosd(x(A)))) → dVHIf(d306090 ≤ d459045 ∧ d306090 ≤ dVH, 1, 0) → is306090If(d459045 < d306090 ∧ d459045 < dVH, 1, 0) → is459045If(dVH < d306090 ∧ dVH < d459045, 1, 0) → isVHIf(y(A) > 0, acosd(x(A)), π + acosd((-x(A)))) → thetaPolygon(O, A, B) → Triangle306090, b, o, aPolygon(O, A, B) → Triangle459045, b_1, o_1, a_1Polygon(O, A, B) → TriangleVH, b_2, o_2, a_2Sequence((cos(Element[Angles459045, k]), sin(Element[Angles459045, k])), k, 1, 4) → Pts459045Sequence((cos(Element[AnglesVH, k]), sin(Element[AnglesVH, k])), k, 1, 4) → PtsVHSequence((cos(Element[AnglesAll, k]), sin(Element[AnglesAll, k])), k, 1, Length[AnglesAll]) → PtsAllElement(AnglesAllLabels, 2) → FailRandom(1, 14) → randIntIf(π / 2 < theta ∧ theta < ((3 * π)) / 2, "-", "") → negCosIf(tan(theta) < 0, "-", "") → negTanAngle(O2, O, A) → alphaGreenIf(theta ≟ π / 3 ∨ theta ≟ (2 * π / 3) ∨ theta ≟ (4 * π / 3) ∨ theta ≟ (5 * π / 3), 1) → isTall306090If(theta ≟ π / 6 ∨ theta ≟ (5 * π / 6) ∨ theta ≟ (7 * π / 6) ∨ theta ≟ (11 * π / 6), 1) → isSkinny306090If(theta ≟ π / 4 ∨ theta ≟ (3 * π / 4) ∨ theta ≟ (5 * π / 4) ∨ theta ≟ (7 * π / 4), 1) → isReal459045If(theta ≟ 0 ∨ theta ≟ π ∨ theta ≟ (2 * π), 1) → isHPoint(xAxis) → CPoint(xAxis) → DPoint(xAxis) → EPoint(xAxis) → FPoint(yAxis) → GPoint(yAxis) → HPoint(yAxis) → IPoint(yAxis) → JPoint(c_1) → A_1Point(c_2) → A_2Angle(O2, O, A) → alphaRedAngle(O2, O, A) → alphaBluePoint(c_3) → A_3If(y(A_3) > 0, acosd(x(A_3)), π + acosd((-x(A_3)))) → theta_1If(π < theta ∧ theta < (2 * π), "-", "") → negSin
AI 绘图提示语参考
画一个单位圆,并在圆上标记出30°、45°、60°等特殊角度对应的点,连接这些点和原点形成三个特殊直角三角形。同时,在坐标轴上标出单位圆的投影点,并显示这些角度的三角函数值。用不同颜色区分不同角度的三角形,并标注角度值和三角函数值。
以上提示语为根据原始绘图命令整理而来,仅供参考。