一、知识梳理(1)函数的定义域函数的定义域即使函数有意义的自变量x的取值范围.一般来说,整式函数的定义域是全体实数;分式函数的定义域由分母不为零确定;无理函数分两种情况,根指数为奇数的,定义域是全体实数,根指数为偶数的,定义域由被开方数不小于零确定; First, the knowledge combing (1) the definition of the function domain The definition of the domain function even if the function is meaningful range of the argument x. In general, the domain of the integer function is the real number; the domain of the fractional function by the denominator is not Zero is determined; the irrational function is divided into two cases, the root index is odd, the domain is all real numbers, the root index is even, and the domain is determined by the number of squared squares not less than zero;