二次函数是中学数学课的一个重要内容,这部分知识是在初中学习的,高中教材中并没有专门的章节讲解它,但是到了高中,由于数学知识的增多,思维能力的增强,就能够以二次函数为生长点演变出许多新的内容。如果说,二次函数的题目在初中阶段还是一潭死水的话,那么到了高中,二次函数的题目就变成 The quadratic function is an important part of the middle school mathematics class. This part of the knowledge is studied in junior high school. There is no specific chapter in high school textbooks to explain it, but in high school, due to the increase of mathematics knowledge and the enhancement of thinking ability, The quadratic function evolves many new contents for the growing point. If we say that the subject of the quadratic function is still a drop of water in the junior high school, then in high school, the subject of the quadratic function becomes