【高三大一微積分】多變量函數的微積分篇｜13｜相對、絕對極值、鞍點｜觀念講解

Picked one by one from a mixed channel; title passed two strict editor passes and the clickbait rules.

A 24-minute video from 數學老師張旭: “【高三大一微積分】多變量函數的微積分篇｜13｜相對、絕對極值、鞍點｜觀念講解”.

Video by 數學老師張旭, played through YouTube's embedded player.