[ log
( logx)] = log
[ log
( logy)] = log
[ log
( logz)] = 0，试比较x、y、z的大小． 
[ log( logx)] = log[ log( logy)] = log[ log( logz)] = 0，试比较x、y、z的大小． 解析：由log
[ log
( logx)] = 0得，log( logx)= 1，logx =
，即x = 2
；
由log
[ log
( logy)] = 0得，log( logy) = 1，logy =
，即y =3
；
由log
[ log
( logz)] = 0得，log( logz) = 1，logz =
，即z = 5
．
∵y =3= 3
= 9
，∴x = 2= 2
= 8，∴y＞x，
又∵x = 2= 2
= 32
，z = 5= 5
= 25，∴x＞z．
故y＞x＞z．