笔者有幸参与了一次“树人杯”评优课活动,课题是苏教版高中数学必修5第三章第4节“基本不等式√ab≤(a+b)/2(a≥0,b≥0)”.经历了备课、听课、评课三个环节,对这节课内容的引入有一些粗浅的感悟. I was fortunate enough to participate in a “tree Cup ” evaluation class activities, the subject is the Sujiao version of high school mathematics compulsory 5 Chapter III, Section 4 “basic inequality √ab≤ (a + b) / 2 (a ≥ 0 , b≥0) ”. Experienced the preparation, listening to lectures, evaluation of the three links, the introduction of this class content has some superficial insights.