在初中教材中,对二次函数作了较详细的研究,由于初中学生基础薄弱,又受其接受能力的限制,这部份内容的学习多是机械的,很难从本质上加以理解。进入高中以后,尤其是高三复习阶段,要对他们的基本概念和基本性质(图象以及单调性、奇偶性、有界性)灵活应用,对二次函数还需再深入学习。一、进一步深入理解函数概念初中阶段已经讲述了函数的定义,进入高中后在学习集合的基础上又学习了映射,接着重新学习函数概念,主要是用映射观点来阐明函数,这时就可以用学生已经有一定了解的函数,特别是二次函数为 In junior high school teaching materials, the quadratic function has been studied in more detail. Due to the weak foundation of junior middle school students and their limited ability to accept, this part of the content is mostly mechanical in nature and difficult to understand in essence. After entering high school, especially during the third year of senior high school, we must further study the quadratic function by applying their basic concepts and basic properties (image, monotonicity, parity and boundedness) flexibly. First, further understanding of the concept of function has been described in the junior high school has defined the function into the high school after learning the collection on the basis of learning the mapping, and then re-learn the concept of the function, the main idea is to use map mapping function, then you can use Students already have some knowledge of functions, especially quadratic functions