向量的投影

GeoGebra 命令及参数

1. Line(B, C) → r
2. Ray(C, B) → h
3. OrthogonalLine(A, h) → i
4. If(a ≟ 0 ∨ a ≟ 1, "", If[a ≟ -1, "-", "" + a]) → a1
5. If(c ≟ 0 ∨ c ≟ 1, "", If[c ≟ -1, "-", "" + c]) → c1
6. If(d ≟ 1, "+", If[d ≟ -1, "-", If[(d > 1) ∧ c ≟ 0, "" + d, If[(d > 1) ∧ (c ≠ 0), "+" + d, "" + d]]]) → d1
7. If(b ≟ 1, "+", If[b ≟ -1, "-", If[(b > 1) ∧ a ≟ 0, "" + b, If[(b > 1) ∧ (a ≠ 0), "+" + b, "" + b]]]) → b1
8. If(a ≟ 0, "", text3) → a11
9. If(b ≟ 0, "", text4) → b11
10. If(c ≟ 0, "", text5) → c11
11. If(d ≟ 0, "", text6) → d11
12. Vector(C, A) → u
13. Vector(C, B) → v
14. Ray(C, A) → f
15. OrthogonalLine(B, f) → k
16. Intersect(i, r) → D
17. Segment(A, D) → g
18. Angle(A, D, C) → α
19. Vector(C, D) → w
20. Angle(C, D, A) → β
21. FractionText(l / n) → text18
22. FractionText(o / n) → text19
23. If((c ≠ 0) ∧ (d > 0), "+", "") → sig
24. Midpoint(C, A) → E
25. Midpoint(C, B) → F