1.忽视定义域错求定义域 例1 若函数f(2x)的定义域为[-1,1],则f(log2x)的定义域为_____. 错解 因为f(2x)的定义域为[-1,1],所以 log2x∈[-1,1],所以 x∈[1/2,2]. 分析 函数定义域是指函数自变量的取值集合,所以f(2x)的定义域即x∈[-1,1],则 2x∈[1/2,2],所以f的作用范围是[1/2,2]上的实数,现在f 1. Ignore definition domain Error definition domain Example 1 If the domain of function f(2x) is [-1,1], then the domain of f(log2x) is _____. The wrong solution is because of the domain of f(2x). Is [-1,1], so log2x ∈ [-1,1], so x ∈ [1/2, 2]. Analysis function definition domain refers to the set of values ​​of function arguments, so the definition of f (2x) The domain is x∈[-1,1], then 2x∈[1/2,2], so the scope of f is the real number on [1/2,2], now f