載入中... 相關課程 Back 【一般】等差級數:前n項的和有最大值 登入觀看 ⇐ Use this menu to view and help create subtitles for this video in many different languages. You'll probably want to hide YouTube's captions if using these subtitles. 【一般】等差級數:前n項的和有最大值 上傳學習單 下載學習單