(4)y=lnx(x≠0) 解当x<0时,y’=[In(-x) 当x>0时,y=nxy=21;即nxy (5)y=x(a∈R) 解:x2=l“=c2hx:(x)=(em)y=ex.(almx) au (6)y=tan 解p”=(an1y·=se2l() sec8 解 0 , [ln( )]' 当 x y x  = − = 时  1 0 , (ln ) ; x y x x 当  = = 时   1 (ln ) . x x 即  = ln ln x x x e e    解 = = ln ln ( ) ( ) ( ln ) x x x e e x     = =      (4) ln ( 0) y x x =  (5) ( ) y x R  =  1 1 x x x     − =   = 1 1 x x − = − 1 (6) tan y x = 1 1 1 y' (tan )' sec ( )' x x x 解 = = 2 1 1 sec x x = −