用抛物线解四次方程

GeoGebra 命令及参数

1. Parabola(A_1, f) → c
2. Line(A_1, f) → g
3. Intersect(c, g) → B, C
4. Segment(B, C) → l
5. OrthogonalLine(A_1, f) → i
6. Intersect(c, i, 1) → A
7. Circle(A, b) → d
8. Intersect(d, i, 1) → D
9. Circle(A, l) → e
10. Circle(A, k) → h
11. Intersect(e, i, 2) → I
12. Intersect(h, i, 1) → K
13. Semicircle(K, I) → p
14. Line(A, f) → j
15. Intersect(p, j) → L,
16. Circle(D, L) → r
17. Intersect(r, c) → N, M, ,
18. Segment(N, M) → m
19. Segment(D, L) → n
20. Segment(D, N) → t
21. Segment(D, M) → a
22. Segment(L, A) → f_1
23. Intersect(i, m) → O
24. Segment(O, M) → x_1