| xn | ||
czy to ma być ∑n=1,... | ? | |
| 42n2 |
| 1 | ||
gdzie an = | ||
| 16n2 |
| an+1 | ||
limn→+∞ | = | |
| an |
| 1 | 16n2 | |||
limn→+∞ | * | = | ||
| 16(n+1)2 | 1 |
| n2 | ||
limn→+∞ | = | |
| n2+2n+1 |
| n2*1 | ||
limn→+∞ | = | |
| n2(1+2n+1n2 |
| 1 | 1 | |||
limn→+∞ | = | = 1 | ||
| 1+2n+1n2 | 1+0+0 |
| 1 | ||
czyli R = | = 1 | |
| 1 |
| 1 | ||
dla x=1 masz ∑ | czyli oczywiście zbieżny | |
| 16n2 |
| (−1)n | ||
dla x= −1 masz ∑ | naprzemienny zbieżny | |
| 16n2 |
