| (n+3)! | ||
an = | ||
| 3n |
| n+4 | ||
an+1 = | ||
| 3n+1 |
| n+4 | (n+3)! | 3n(n+4)!−3n+1(n+3)! | ||||
an+1 − an = | − | = | = | |||
| 3n+1 | 3n | 3n+1*3n |
| 3n(n+4)(n+3)(n+2)!−3n+1(n+3)(n+2)! | [3n(n+3)(n+2)!][n+4−3] | |||
= | = | = | ||
| 32n+1 | 32n+3 |
| (n+3)(n+2)!(n+1) | ||
= | ||
| 3n +3 |
Pomocy!
| an+1 | (n+4)! | 3n | n+4 | 1 | 4 | |||||||
lepiej zbadać | = | * | = | = | n+ | >1, | ||||||
| an | 3n+1 | (n+3)! | 3 | 3 | 3 |
| 1 | 4 | |||
a mógłbyś wytłumaczyć skąd wiadomo że | n + | >1 ? | ||
| 3 | 3 |
| 4 | 1 | ||
to część stała >1, ponadto | n rośnie , wiec wszystko na pewno >1 | ||
| 3 | 3 |
