2.im(1+-)2=e im(1+a)4=e x→0 2→>0 例8求极限lim(1+ 2x x→0 解lim(1+-)2X=im(1+)]=e2 x→0 般:lim[1+- (x) e (x)→0 或lim1+v(x)x)=e w(x)→>0) . 1 lim(1 2x x x + → . 2 e + = e. → ( ) 1 ( ) 0 lim [1 ( )]w x w x 或 w x 例8 求极限 一般： + = e → ( ) ( ) ] ( ) 1 lim [1 u x u x u x + = → x x x 2 ) 1 解 lim(1 2 ) ] 1 lim[(1 + = → x x x + = e → x x x ) 1 2. lim(1 + = e → u u u 1 0 lim(1 )