判别式

GeoGebra 命令及参数

1. If(c < 0, "-", "+") → signcc
2. If(c ≠ 0, signcc + absc, "") → text6
3. If(b < 0, "-", "+") → signbb
4. If(a < 0, "-", "") → signa
5. If(a ≟ 0, "", If[absa ≟ 1, signa + "x^2", a + "x^2"]) → text5
6. If(b ≟ 0, "", If[a ≠ 0 ∧ absb ≠ 1, signbb + absb + "x", signbb + "x"]) → text7
7. If(b < 0, "-", "") → signb
8. If(c < 0, "-", "") → signc
9. If(a < 0, "-", "+") → signaa
10. If(b < 0, "(" + b + ")", "" + b) → text3
11. If(c < 0, "(" + c + ")", "" + c) → text4
12. If(a < 0, "(" + a + ")", "" + a) → text11
13. Intersect(d, xAxis) → A, B
14. Point(e) → C
15. Point(e) → D_1
16. Point(f) → E
17. Point(f) → F