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本文所指的复合函数是指在初中现阶段所出现的用整式表示的函数、用分式表示的函数、用二次根式表示的函数和用零指数幂或负整数指数幂表示的函数以及两两混合在一个解析式中的函魏求这类函数自变量的取值范围(即函数的定义域)是近年来中考试卷的重点内容,也是命题的热点内容.那么,怎样求上述复合函数自变量的取值范围呢?为解决此问题,首先要了解如下几点:(1)若函数解析式是整式,则自变量的取值范围是全体实数.(2)若函数解析式是分式,则自变量的取值范围是使分母不为零的一切实数.(3)若函数解析式是二次根式,则自变量的取值范
The complex functions referred to in this paper are the functions represented by integers, the functions expressed by fractions, the functions expressed by quadratic roots and exponentiation exponentiated by zero exponents or negative integers at the present stage of junior high school, Two kinds of mixed in a analytical function of the letter to find the range of function arguments (ie, the function of the domain) is the focus of recent examination papers, but also the hot topic proposition. So how to find the above composite function since To solve this problem, we must first understand the following points: (1) If the function analytic is an integer, then the range of independent variables is the whole real number. (2) If the function analytic is fractional , Then the value of the independent variable is the real number that makes the denominator non-zero. (3) If the function’s analytic formula is quadratic, then the value of the independent variable