二次函数是初中代数的一个难点 ,是数形结合的一个典型内容 ,对抽象思维的训练起着不可替代的作用 ,更是高中阶段进一步学习函数的一个基础 .二次函数是历来各省市中考的重点考查内容 ,而学会求二次函数解析式又是掌握该项内容的一个重要指标 .因此下面就谈谈求二次函数解析式 The quadratic function is a difficult point of junior high school algebra, a typical content of the combination of numbers and shapes, plays an irreplaceable role in the training of abstract thinking, and is a basis of further learning functions in the senior high school. The quadratic function is the historical examination of all provinces and cities. The focus of the examination is to examine the content, and to learn the quadratic function analytical formula is an important indicator of mastering the content. Therefore, the following discussion of the quadratic function analytical formula