【正文】
100fexxf xxx???????. 0 )( 處連續(xù)在點 ?? xxfxaxaxxx x100)1(l oglim)1(l oglim ??????)(loglim 0 xfax ?? .l o g)](l i m[l o g0 exf axa ?? ?特別有 .1)1l n (l i m0??? xxx 當 0?x 時, 0?t , ),1(l og ,1 ) 2 ( txat ax ???? 則令,lnl og 1)1(l ogl i m1l i m00aettxaaatxx???????.11lim 0??? xe xx特別有( 3 )當 0?? 時,結論顯然成立 . 當 0?? 時,xxxexx x )1l n ()1l n (11)1( )1l n ( ????????? ??? xxxexxxxxx)1l n (l i m)1l n (1l i m1)1(l i m0)1l n (00???????????????.11 ??????, 0 時當 ?x : 論結要重, ln 1 )1(l og xa~xa ?, )1ln( x~x?, ~ 1 xe x ?,ln1 ax~a x ?.1)1( x~x ?? ??則若 ,)(lim,0)(lim00BxvAxu xxxx ??? ??). ( )(lim 0)(0????是有限數或其中 xAxu Bxvxx例 7 .求下列極限: ( 1 ) xxxxx ln1lim1??; 解 : 1lnlnlimln1limln1lim1ln11 ???????? xxxxxxexxxxxxxxx. ( 2 ))41l n ()51l n (limxxx ?????; 解 : .0)45(l i m45l i m)41l n ()51l n (l i m ??????????????xxxxxxxx 解 :令2??? xt,當2??x時, 0?t , ttxxtx c o t0t a n2)( c o sl i m)( s i nl i m ?????.1021l i mt a nc o s1l i m200 ???? ???eee ttttttttttt t an1c os1c os10})]1(c os1{[lim ???????xxx t a n2)( s i nlim ) 3 (??習 題 2 ( 1)( 4)( 6)( 7); 3 ( 2)( 5)( 7)( 8)( 10)( 13);4 ( 3) . 作 業(yè)