1998年全国卷文科★★★★★★★★★★—(0)5. 函数 f(x)=1x(x≠0)\displaystyle f(x) = \frac{1}{x}(x \ne 0)f(x)=x1(x=0) 的反函数 f−1(x)=f^{-1}(x) =f−1(x)=（ ）A. x(x≠0)x (x \ne 0)x(x=0)B. 1x(x≠0)\displaystyle \frac{1}{x}(x \ne 0)x1(x=0)C. −x(x≠0)-x (x \ne 0)−x(x=0)D. −1x(x≠0)\displaystyle -\frac{1}{x}(x \ne 0)−x1(x=0)查看解析查看变式题