| x2 | ||
mam napisać szereg Maclaurina | określić promień zbieżności tego szeregu | |
| x3+8 |
| 1 | |
= ∑n=0∞xn | |
| 1 − x |
| x2 | x2 | 1 | x2 | 1 | |||||
= | * | = | * | = | |||||
| x3 + 8 | 8 | 1 + (x/2)3 | 8 | 1 − (−(x/2)3) |
| x2 | x | x2 | x3n | |||||
= | * ∑(−( | )3)n = | * ∑(−1)n * | = | ||||
| 8 | 2 | 8 | 8n |
| x3n + 2 | ||
= ∑(−1)n | ||
| 8n +1 |
| 1 | ||
R = | ||
| limn→∞3n+2√|(−1)n/8n+1| |
| 1 | ||
Stąd R = | ||
| 2 |