含参数的一次函数、二次函数在某区间上根的问题,是初中学习中综合性较强的内容.此类题目的解答一是有其特殊的方法,另外如果不填容易出现错误.现举例如下:例1已知函数f(x)=3ax-2a+1在区间[-1,1]上存在x0,使f(x0)=0,求实数a的取值范围.分析易知f(x)的图象在区间[-1,1]上为一条 The problem of roots with a function or a quadratic function in a certain interval is the content of comprehensiveness in junior high school learning. The answer to such a topic is its special method, and if it is not filled in, it is prone to errors. An example is as follows: Example 1 Known function f(x)=3ax-2a+1 There is x0 in the interval [-1,1] so that f(x0)=0 and the range of real numbers a is determined. The image of (x) is a line in the interval [-1,1]