向量与二次方程的几何作图

GeoGebra 命令及参数

1. Point(Sequence[A + (i, 0), i, 1, 20, 1]) → B
2. Vector(B, C2) → v
3. Sequence((x(B) + (Length[v] * cos(t°)), y(B) + (Length[v] * sin(t°))), t, 0, 355, 5) → UPoints
4. Vector(A, C1) → u
5. Sequence((x(A) + (Length[u] * cos(t°)), y(A) + (Length[u] * sin(t°))), t, 0, 355, 5) → VPoints
6. Intersect(Ray[D, Rotate[D + (1, 0), 40°, D]], Ray[E, Rotate[E - (1, 0), (-(55°)), E]]) → F
7. Segment(F, D) → k
8. Segment(E, F) → j
9. DynamicCoordinates(C1, x(ClosestPoint[VPoints, C1]), y(ClosestPoint[VPoints, C1])) → C
10. Segment(A, C) → f
11. Segment(A, B) → g
12. DynamicCoordinates(C2, x(ClosestPoint[UPoints, C2]), y(ClosestPoint[UPoints, C2])) → C'
13. Segment(C', B) → h
14. Intersect(Ray[A, C], Ray[B, C']) → G
15. Polygon({A, B, G}) → t1
16. If(C ≟ G ∧ C' ≟ G, true, false) → closed1
17. Segment(D, E) → i
18. Polygon(D, E, F) → t3, l, m, n
19. Angle(E, D, F) → α
20. Angle(B, A, C) → β
21. Angle(F, E, D) → γ
22. Angle(C', B, A) → δ