| x | x | x | |||
+( | )2+( | )3+....<2 | |||
| x+1 | x+1 | x+1 |
| x | x | |||
geometrycznego w którym a1= | i q= | zbieżna do sumy | ||
| x+1 | x+1 |
| a1 | x/(x+1) | |x| | ||||
s= | = | , gdy |q|<1 ⇔ | <1 ⇔ x>− 12 , a | |||
| 1−q | 1−x/(x+1) | |x+1| |
| a1 | x | |||
s<2 i x >−12 ⇒ | < 2 ⇔ | < 2 ⇒ x<2 i x >−12 ⇔ | ||
| 1−q | x+1−x |