二次函数中有一些典型的涉及范围的问题,比如函数的取值范围、字母系数的取值范围等等.这类问题往往会和不等式结合起来,而且还会需要进行全面的讨论才能得出正确的结果.下面的问题就是训练我们解答这种问题的典型考题.1.字母的取值范围例1二次函数y=ax~2+bx+c(a≠0)的图象所示, There are some typical range-related problems in quadratic functions, such as the range of functions, the range of letter coefficients, etc. Such problems tend to be combined with inequalities and require extensive discussion to arrive at Correct results. The following questions are the typical questions for training us to answer this question: 1. Letter range Example 1 As shown in the image of the quadratic function y = ax ~ 2 + bx + c (a ≠ 0)