Radius of Convergence

Core Sentence / 核心句

The radius of convergence is how far from the center a power series converges.

中文理解:收敛半径表示从中心点往左右多远以内 power series 会收敛。

Formula / 公式或规则

Find the open interval first, usually by Ratio Test; the radius is half the interval length.

When To Use / 什么时候用

看到 power series centered at 、find radius,就求 radius of convergence。

Watch Out / 易错点

radius 不包括 endpoint behavior;endpoint belongs to interval of convergence.

Search and Source Mentions / 搜索与出现位置

Mentioned In / 出现位置

Connected Notes / 连接