什么样的课才是好课,往往也是仁者见仁,智者见智.笔者认为,一堂好课最起码应该具备根、魂、痕三个特点.一、课例介绍本节课是人教版九年级上册《二次根式》第一课时的内容,它是前面学习的数的开方的后续,也是学习二次根式的运算的基础.二次根式在整个初中阶段起着重要的作用,贯穿始终,是为后续学习夯实基础的重要内容.本节课是在数的开方的有关知识的基础 What kind of class is a good lesson, often seen by benevolent persons, the wise see wisdom. The author believes that a good class should at least have the three characteristics of the root, soul, and trace. First, the class introduction This class is the 9th grade The contents of the first lesson of the “Secondary Roots” book, which is the follow-up to the preceeding numbers, is also the basis for learning secondary roots. The secondary roots play an important role throughout the junior middle school. It is an important part of the foundation for follow-up study. This lesson is the basis for the knowledge of the prescribing