【正文】
????? ?????????? ???????????????????????????????.),(21)(21),(),(21)()(21),()(4)(04)(0)(4)(0)(4)(4)(4)(222222222222?????????????????????????????????????dddddddddtefaetateftefaeetatxutaxttaxxxt taxt taxxxtaxtax Company Logo Click to edit title style 例 3.求解半無限長弦的強(qiáng)迫振動(dòng)的混合問題 ??????????????????0)0,(0)0,(),(l i m,0),0()0,0(,c os)(2xuxutxututxxtfuautxxxtt,有界?解: ????????????????有界),(l i m,0),0()0(,c o s)(),(),(222pxUpUxxapFpxUapxpxUx2 ?dd 2? ? ),(),( pxUtxu ? ? ? )()( pFtf ?記 ? , ? xap pFececpxU xapxap?? c os)(),( 22221 ???? ? Company Logo Click to edit title style ),(lim pxUx ??? 01 ?c0),0( ?pU2222)(appFc???????????? ???? xapexappFpxU ?? c o s)(),(222注意到 ? taaap ??? s i n112221 ????????,利用卷積定理 令 ?)(tg ? ?????????? ?ttafatftaaap pF02221 )(s i n)(1)(s i n1)( ???????? d? 逆變換 , 根據(jù)延遲性質(zhì) )()(c o s)(),( axtuaxtgxtgtxu ???? ?)(tu 是單位階躍函數(shù) Company Logo Click to edit title Text 1 Text 2 Text 3 Text 4 本章主要內(nèi)容簡要回顧 LOGO