单位圆动画
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①本范例演示单位圆上点、向量与三角函数值(正弦、余弦)的动态关系;②涉及核心数学概念包括单位圆、三角函数、向量、解析几何;③作图要点运用了If、Intersect、Point、Segment、CircleArc、OrthogonalLine、Circle、Polygon、CircleSector、LaTeX、Numerator、Denominator等GeoGebra命令与对象;④适合高中数学教学,用于直观理解三角函数与几何图形的联系,增强空间想象能力。
GeoGebra 命令及参数
If(smooth ≟ 0, ((step1 + step2 + step3 + step4 + step5 + step6 + step7 + step8 + step9 + step10 + step11 + step12 + step13 + step14 + step15 + step16) * π / 6) + ((2 * π) * n), smoothplay) → argumentIntersect(xAxis, yAxis) → CPoint(snap) → DPoint(p) → ZPoint(snap) → BIf(n ≥ 1, 359.99 + (0.01 * (n^(2) - 1) / n^(2)), 0.01 / (n^(2) + 1)) → closeIntersect(xAxis, yAxis) → AIf(Row[A2] / 2 ≟ ceil(Row[A2] / 2), LaTeX["\text{" + (Row[A3]) + "\pi}"], Row[A3] + 1) → A4If(Row[A3] / 2 ≟ ceil(Row[A3] / 2), LaTeX["\text{" + (Row[A4]) + "\pi}"], Row[A4] + 1) → A5If(Row[A4] / 2 ≟ ceil(Row[A4] / 2), LaTeX["\text{" + (Row[A5]) + "\pi}"], Row[A5] + 1) → A6If(Row[A5] / 2 ≟ ceil(Row[A5] / 2), LaTeX["\text{" + (Row[A6]) + "\pi}"], Row[A6] + 1) → A7If(Row[A6] / 2 ≟ ceil(Row[A6] / 2), LaTeX["\text{" + (Row[A7]) + "\pi}"], Row[A7] + 1) → A8If(Row[A7] / 2 ≟ ceil(Row[A7] / 2), LaTeX["\text{" + (Row[A8]) + "\pi}"], Row[A8] + 1) → A9If(Row[A8] / 2 ≟ ceil(Row[A8] / 2), LaTeX["\text{" + (Row[A9]) + "\pi}"], Row[A9] + 1) → A10If(Row[A9] / 2 ≟ ceil(Row[A9] / 2), LaTeX["\text{" + (Row[A10]) + "\pi}"], Row[A10] + 1) → A11If(Row[A10] / 2 ≟ ceil(Row[A10] / 2), LaTeX["\text{" + (Row[A11]) + "\pi}"], Row[A11] + 1) → A12If(Row[A11] / 2 ≟ ceil(Row[A11] / 2), LaTeX["\text{" + (Row[A12]) + "\pi}"], Row[A12] + 1) → A13If(Row[A12] / 2 ≟ ceil(Row[A12] / 2), LaTeX["\text{" + (Row[A13]) + "\pi}"], Row[A13] + 1) → A14If(Row[A13] / 2 ≟ ceil(Row[A13] / 2), LaTeX["\text{" + (Row[A14]) + "\pi}"], Row[A14] + 1) → A15If(Row[A14] / 2 ≟ ceil(Row[A14] / 2), LaTeX["\text{" + (Row[A15]) + "\pi}"], Row[A15] + 1) → A16If(Row[A15] / 2 ≟ ceil(Row[A15] / 2), LaTeX["\text{" + (Row[A16]) + "\pi}"], Row[A16] + 1) → A17If(Row[A16] / 2 ≟ ceil(Row[A16] / 2), LaTeX["\text{" + (Row[A17]) + "\pi}"], Row[A17] + 1) → A18If(cosine, LaTeX["\text{\cos}"], If[sine, LaTeX["\text{\sin}"], LaTeX["\text{\tan}"]]) → functiontextIf(cosine, LaTeX["\fcolorbox{black}{white}{\text{The Cosine Function}}"], If[sine, LaTeX["\fcolorbox{black}{white}{\text{The Sine Function}}"], LaTeX["\fcolorbox{black}{white}{\text{The Tangent Function}}"]]) → TitleIf(cosine, LaTeX["\fcolorbox{black}{white}{\text{The Cosine Function}}"], If[sine, LaTeX["\fcolorbox{black}{white}{\text{The Sine Function}}"], LaTeX["\fcolorbox{black}{white}{\text{The Tangent Function}}"]]) → TitleguideSegment((1, 0), (-1, 0)) → b_1Segment((0, 1), (0, -1)) → h_2Segment(A, D_1) → fCircleArc(A, (1 / 3 * D), (1 / 3 * D_1)) → gCircleArc(A, (2 / 3 * D), (2 / 3 * D_1)) → hIf(0 < argument ≤ (2 * π), (1 / 3 * D_1), If[argument > (2 * π), (2 / 3 * D_1)]) → EOrthogonalLine(E, f) → iCircle(E, arrowlength) → qIntersect(q, i, 1) → FOrthogonalLine(F, i) → jCircle(F, arrowwidth) → rIntersect(r, j, 1) → GIntersect(r, j, 2) → HPolygon(E, H, G) → t1, g_1, e_1, h_1CircleSector(A, (1 / 3, 0), (1 / 3 * D_1)) → cIf(sine, If[0 ≤ x ≤ argument, sin(x)], If[cosine, If[0 ≤ x ≤ argument, cos(x)], If[0 ≤ x ≤ argument, tan(x)]]) → trigLaTeX("\text{\frac{\sqrt{3}}{2}}") → s32LaTeX("\text{\minus\frac{\sqrt{3}}{2}}") → ns32LaTeX("\text{\frac{\sqrt{2}}{2}}") → s22LaTeX("\text{\minus\frac{\sqrt{2}}{2}}") → ns22LaTeX("\text{\frac{1}{2}}") → ohLaTeX("\text{\minus\frac{1}{2}}") → nohLaTeX("\text{0}") → zeroLaTeX("\text{1}") → oneLaTeX("\text{\minus 1}") → noneCircleSector(A, (2 / 3, 0), (2 / 3 * D_1)) → dNumerator(argument / π) → numDenominator(argument / π) → denomIf(num ≠ 1 ∧ denom ≠ 1, LaTeX[(((("\text{\frac{" * LaTeX[num]) * "\pi}{") * LaTeX[denom]) * "}}")], If[num ≟ 1 ∧ denom ≠ 1, LaTeX[(("\text{\frac{\pi}{" * LaTeX[denom]) * "}}")], If[denom ≟ 1 ∧ num ≠ 1 ∧ num ≠ 0, LaTeX[(("\text{" * LaTeX[num]) * "\pi}")], If[num ≟ 0, LaTeX["\text{0}"], LaTeX["\text{\pi}"]]]]) → text34If(num ≠ 1 ∧ denom ≠ 1, LaTeX[(((("\text{\frac{" * LaTeX[num]) * "\pi}{") * LaTeX[denom]) * "}}")], If[num ≟ 1 ∧ denom ≠ 1, LaTeX[(("\text{\frac{\pi}{" * LaTeX[denom]) * "}}")], If[denom ≟ 1 ∧ num ≠ 1 ∧ num ≠ 0, LaTeX[(("\text{" * LaTeX[num]) * "\pi}")], If[num ≟ 0, LaTeX["\text{0}"], LaTeX["\text{\pi}"]]]]) → text34guideIf(0 ≤ argument ∧ argument < (2 * π), argument, If[(2 * π) ≤ argument ∧ argument < (4 * π), argument - (2 * π), argument - (4 * π)]) → argforreadIf(smooth ≟ 1, LaTeX["y"], If[cosine, LaTeX[cosoutput], If[sine, LaTeX[sinoutput], LaTeX[tanoutput]]]) → outputSegment(I, Tracepoint) → lSegment(Tracepoint, J) → mIf(smooth ≟ 1, LaTeX["y"], If[cosine, LaTeX[cosoutput], If[sine, LaTeX[sinoutput], LaTeX[tanoutput]]]) → guideoutputIf((¬(D_1 ∈ snap)) ∨ smooth ≟ 1, LaTeX["x"], If[showdegrees, LaTeX[degtext], LaTeX[text34]]) → guidextextIf((¬(D_1 ∈ snap)) ∨ smooth ≟ 1, LaTeX["x"], If[showdegrees, LaTeX[degtext], LaTeX[text34]]) → graphxtextIf(tangent, "tan", If[cosine, "cos", If[sine, "sin"]]) → functext