为了引出反函数的概念,我以函数y=2x∈[1,2],为例子进行了如下的分析:首先说明函数y=2x,x∈[1,2]的自变量为x,定义域为[1,2],函数值为y,值域为[2,4],对应法则是“乘以2”;然后从y=2x中解出x得到x=1/2y之后,进行了如下的解释:“对照函数的定义,它可以看作是一个以y为自变量,x为函数的函数,如果令其定义域为 In order to elicit the concept of an inverse function, I use the function y=2x∈[1,2] as an example to perform the following analysis: First, the function y=2x, the argument of x∈[1,2] is x, and the domain is defined. For [1,2], the function value is y, the value range is [2,4], and the corresponding rule is ”multiply by 2“; then solve x from y=2x to get x=1/2y, then proceed. The following explanation: ”Compare the definition of the function, it can be seen as a function that takes y as an argument and x is a function, if its domain is defined as