二次函数是初中数学的重要内容之一,也是学习的一个难点,同时又是“数形结合”思想方法体现得很充分的一个章节。在此特对利用数形结合思想解决二次函数的问题进行简单的归纳分析。一、由函数图象可得函数中的a、b、c及有关代数式的值例(如图1)由函数图象可以直接得二次函数的基本性质(如函数的变化趋势),此外,在y=ax2+bx+c(a≠0)中还能得以下结论: The quadratic function is one of the important contents of junior high school mathematics, and also a difficult point of learning. At the same time, it is also a section fully embodying the idea of ​​“combination of numbers and forms”. In this special on the use of combination of ideas to solve the quadratic function problem simple induction. A, b, c and algebraic values ​​(Figure 1), which are obtained from the function image. The basic properties (such as the trend of the function) of the quadratic function can be directly obtained from the function image. In addition, In y = ax2 + bx + c (a ≠ 0) can also be concluded as follows: