余弦函数与单位圆

GeoGebra 命令及参数

1. Point(Ray[(0, 0), (-1, 0)]) → B
2. Rotate(A, θ, B) → P
3. Rotate(A, θ, B) → A'
4. Angle(A, B, A') → α
5. Rotate(A, θ, B) → A'_1
6. Angle(A, B, A'_1) → β
7. Segment(Q, (x(Q), 0)) → e
8. Segment((0, 0), (x(Q), 0)) → g
9. Circle(B, A) → c
10. Segment(B, P) → a
11. Vector((x(B), y(Corner[1])), (x(B), y(Corner[4]))) → u
12. Vector((0, y(Corner[1])), (0, y(Corner[4]))) → w
13. Vector((0, 0), (x(Corner[2]), 0)) → z
14. Sequence(Segment[((0.75 * i), 0), ((0.75 * i), -0.025)], i, 1, 4) → list1
15. Segment(B, (x(P), 0)) → b
16. Segment(P, (x(P), 0)) → h
17. Function(cos((120° * x)), 0, x(Q)) → f
18. Vector(B - (1.2, 0), B + (1.2, 0)) → v
19. Sequence(Segment[(0, (0.5 * i) - 1), (-0.025, (0.5 * i) - 1)], i, 0, 4) → list2
20. Sequence(Segment[(x(B), (0.5 * i) - 1), (x(B) - 0.025, (0.5 * i) - 1)], i, 0, 4) → list3
21. Sequence(Segment[B + ((0.5 * i) - 1, 0), B + ((0.5 * i) - 1, -0.025)], i, 0, 4) → list4
22. Segment(Q, (0, y(Q))) → d
23. Point(Ray[(0, 0), (-1, 0)]) → B_1
24. Rotate(A_1, θ, B_1) → P_1
25. Rotate(A_1, θ, B_1) → A'_2
26. Rotate(A_1, θ, B_1) → A'_3
27. Circle(B_1, A_1) → c_1
28. Segment(B_1, P_1) → a_1