| (n!)2 | ||
∑ | ||
| (2n)! |
przypomnij mi kryterium d'alemberta zbieżności szeregu
| (n!)2 | ||
an = | ||
| (2n)! |
| ((n+1)!)2 | ||
an+1 = | ||
| (2(n+1))! |
| an+1 |
| ||||||||
= | = | ||||||||
| an |
|
| ((n+1)!)2 | (2n)! | ||
* | = | ||
| (2(n+1))! | (n!)2 |
| (n+1)!(n+1)! | (2n)! | ||
* | = | ||
| (2n + 2)! | n! * n! |
| n! * n! * (n+1)(n+1) | (2n)! | (n+1)(n+1) | |||
* | = | ||||
| 2n!(2n + 1)(2n + 1) | n! * n! | (2n+1)(2n+2) |
| an+1 | (n+1)(n+1) | |||
limn−>∞ | = limn−>∞ | = limn−>∞U{n2 + 2n + | ||
| an | (2n+1)(2n+2) |
| 1 | ||
1}{4n2 + 6n + 2)} = | < 1 | |
| 4 |
chyba się nigdzie nie walnąłem
| 1 | (n!)2*(n+1)2 | 2n! | ||||
an+1 * | = | * | = | |||
| an | 2n!*(2n+1))(2n+2) | (n!)2 |
| (n+1)2 | n+1 | 1+ 1/n | ||||
= | = | = | ||||
| 2(2n+1)(n+1) | 4n+2 | 4 + 2/n |
| 1 | ||
ok dzięki wielkie mnie jakimś cudem wyszło | ale już znalazłem błąd | |
| 3 |