(3)lim x-; → 解 lim x sin-=lim x→0 (4). lim Sin 2x x→>0y-cosx 解lin sin 2x sin 2r 1 n alim 4 x→0x2cosx"x→0(2x)2cosx x-tanx (5).im x→>0x+tanx n x-tan x 解lim lim 0 x→0x+ tanxi→+0,,tanx arcsin (6).lim x->03x 解 lim-令t= arcsin rlim x→>03x t→>03sint38 2 2 0 sin 2 (4).lim ; x cos x → x x 1 (3)lim sin ; x x → x 1 sin 1 lim sin lim 1 x x 1 x x x x → → 解 = = 0 tan (5).lim ; x tan x x → x x − + 2 2 2 2 0 0 sin 2 sin 2 1 lim 4lim 4 x x cos (2 ) cos x x → → x x x x 解 =  = 0 arcsin (6).lim . x 3 x → x 0 0 tan 1 tan lim lim 0 tan tan 1 x x x x x x x x x x → → − − = = + + 解 0 0 arcsin 1 lim arcsin lim x t 3 3sin 3 x t t x → → x t 解 令 = =