‌已知幂级数<img src="https://static.zxtiku.com/wangke/imgs/topic/a32e5c2008a7bc7531af869b31b75022.png"/>在<img src="https://static.zxtiku.com/wangke/imgs/topic/204cd9eb405d4795221b152eebb15dc7.png"/>处收敛，在<img src="https://static.zxtiku.com/wangke/imgs/topic/a0d33a4b6f5e727995f1ae8404618bf0.png"/>处发散，则幂级数<img src="https://static.zxtiku.com/wangke/imgs/topic/b0b35c16479c390bda8c8b737a22feb3.png"/>的收敛域为‏