先根据题目条件写出f(x)f(x)=1/(x-1)则可得：x=1/f(x)+1记反函数为g(x)所求反函数即为g(x)=1/x+1
f(x+1) = 1/x = 1/[(x+1)-1], y = f(x) = 1/(x-1)x -1 = 1/y, x = 1 + 1/y = (y+1)/y, 反函数 y = (x+1)/x
