论文部分内容阅读
根据教科书中有关反函数的定义过程,一般来说,求反函数有三个步骤:1.求原函数的值域;2.从原函数式中解出 x,即用),表示 x;3.x、y 互换,并标注定义域(即原函数的值域).在这三个步骤中,第三步是至关重要的,也只有这一步才能体现映射关系由 A→C变为 C→A.从这个角度去讲,针对 y=f(x)直接把x,y 互换,所得到的 x=f(y)就是 y=f(x)的反函数.这一步既可像习惯上那样放在最后,也可首先去做,
According to the definition process of inverse function in textbooks, in general, the inverse function has three steps: 1. Find the value range of the original function; 2. Solve for x from the original function, ie, use), to represent x; 3. x and y are interchanged, and the definition domain (ie, the domain of the original function) is annotated. In the three steps, the third step is crucial, and only this step can reflect the mapping from A→C to C. →A. From this point of view, x and y are directly swapped for y=f(x), and the resulting x=f(y) is the inverse of y=f(x). This step can be like a habit. If you put it like that at the end, you can do it first.