历年高考试题中函数的知识点和函数思想都占有相当重要的地位,而其中的二次函数犹如一根红线贯穿其中。在初中教材中,对二次函数作了详细的研究,由于初中学生理解能力较差,又受其接受能力的限制,对这部分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、对称性、有界性) The function points and function thoughts of functions in the high examination questions of the past years occupy a very important position, and the secondary functions are like a red line running through them. In junior high school textbooks, a detailed study of quadratic functions was conducted. Due to the poor comprehension ability of middle school students and their limited ability to accept them, the learning of this part is mostly mechanical and difficult to understand in essence. After entering high school, especially in the third year, they must have a basic concept and basic nature (image and monotony, parity, symmetry, and boundedness).