动态单位圆参考：几何作图与参数探索

GeoGebra 命令及参数

1. Intersect(xAxis, yAxis) → A
2. Circle(A, B) → c
3. Rotate(B, 30*°, A) → B'
4. Point(c) → C
5. Segment(A, C) → a
6. OrthogonalLine(C, xAxis) → b
7. Intersect(b, xAxis) → D
8. Segment(A, D) → d
9. Segment(C, D) → e
10. Polygon(A, C, D) → poly1, d_1, a_1, c_1
11. Angle(B, A, C) → β
12. LaTeX(β) → ref
13. LaTeX(f) → text6
14. LaTeX(sin(β)) → text11
15. LaTeX(cos(β)) → text12
16. If(0 < f < π / 2, f, If[π / 2 < f < π, π - f, If[π < f < (3 * π / 2), f - π, If[(3 * π / 2) < f < (2 * π), (2 * π) - f]]]) → Reference
17. LaTeX(Reference) → text5
18. LaTeX(α) → text15