1( )1 1 11( ( ))

1 1 1 1 2(1 ) ( )1 1

xx x

f f xx x x

x

So

1 1(( ) 1) ( ) 1 1 21 1( ( ( )))1 1 2 1 2 3 2(( ) 2) ( )1 1

xx xxf f f x

x x xx

2x

So 3

2x

And from original problem, 1x