初中对于函数的学习要求比较低,对于二次函数这部分知识,学生不容易掌握,尤其二次函数解析式求法是一大难点,现对其略加整理.方法1 最基本的方法是从定义出发,y=ax2+bx+c(a≠0)是二次函数的一般解析式.若知道函数图象上的三个点的坐标,即可求出函数的解析式. The learning requirements of the junior high school for the function is relatively low, for the part of the knowledge of the quadratic function, the students are not easy to grasp, in particular, the analytical method of the quadratic function is a major difficulty, it is now a little bit of consolidation. Method 1 The most basic method is from the definition Starting, y = ax2 + bx + c (a ≠ 0) is the general analytical expression of the quadratic function. If you know the coordinates of the three points on the function image, you can find the analytical expression of the function.