16.设y=f(x)在x=0处可导，f(0)=0,则1im f(x) )=lim(()=(0) x→0 x-0 17极限1im arctan x arctanx lim xIn arctan x lim π =e x-→+o∞ arctan x mxn arctanx lim 元 元 x→+o∞ 2 1 X 2 2 arctan xπl+x2 2 lim X→+00 元 原式=e月0 ( ) ( ) 0 (0) 0, lim x f x y f x x f → x 16.设 = = = = 在 处可导, 则 0 0 ( ) ( ) (0) lim lim (0) x x 0 f x f x f f → → x x − = =  − 2 17. lim arctan x x x →+      =   极限 2 2 lim ln arctan lim arctan x x x x x x e   →+       →+     =   2 ln arctan 2 lim ln arctan lim x x 1 x x x x  →+ →+            =   2 2 2 1 2arctan 1 limx 1 x x x   →+   + = − 2  = − 2 e  − 原式 =