( 1) 1- 1-x 1 1。 Let f (x) = and find f (-x), f (), f (x+1).1+x x f (x)1-x solution: qf (x) =1+x/. F (x) = =1+(-x)1-x1+11+x1-(x 2 x -4 ( 1) f (x) =，g(x)= x+2； X-2 solution: Because the domain of f (x) is (-? , 2) ? (2, +? ), and the domain of g (x) is (-? , +? ), so the definition domains of f (x) and g (x) are different, so f (x) and g (x) are different.

(2) f (x) = (3x - 1)2，g(x)= 3x- 1； Solution: f (x) and g (x) are the same because they have the same domain and corresponding rules. X+ 1。

(3) f (x) = ln，g(x)= ln(x+ 1)-ln(x- 1)； x - 1 x - 1？ 0μx+ 1 & gt； 0 ? √ Solution: The domain of f (x) is (-? -, 1)? ( 1,+? ), the domain of g (x) is >; 0x- 1 & gt； 0 x - 1？ Yes (1,+? ), so the definition domains of f (x) and g (x) are different, so f (x) and g (x) are different. x+ 1 2。

See the figure below for the specific steps to solve other exercises.