确定自变量的取值范围是函数问题中的基础知识，也是中考所考查的重要知识．我们知道，由解析式表达的函数，其自变量的取值范围就是使这个解析式有意义的自变量取值的全体．如果解析式的分母中含有自变量，则需被开方式大于或等于零……，因此，求自变量的取值范围是和解... Determining the value range of the independent variable is the basic knowledge in the function problem, and it is also the important knowledge examined in the examination. We know that the function represented by the analytical expression, its range of values ​​of the independent variable is the whole value of the independent variables that make this analytic meaningful. If the denominator of the analytical formula contains an independent variable, the opening method must be greater than or equal to zero.... Therefore, the range of the independent variable is the reconciliation...