(1) times AX- 1 >: 0 and a >；; 0 gets x> 1/a, so the domain is (1/a, +∞).

(2) Because of a>0, the function y=ax- 1 is increasing function. When 0

That is, when 0

If the root of the equation f(2x)=f- 1(x) is 1, substitute x= 1 to get f(2)=f- 1( 1), that is to say, the inverse function crosses the point (1)