()[()]()fxdxfttdt()[()]FtCFxC()0t(t)x()[()]ttf(t)F()x()xt?125xdxx.xsint,costdt,dxxdxx251tdtttsincossin24“(cos))coscos(ttdt241](cos)cos[costtdt26Ctt3737coscos换元txsintdtttcossin)(sin251回代21xtcos73222211(1)(1)73xxCx121xt第二类换元积分法积分类型换元公式bdxaxfn)(1.tnbnax(正整数)dxxaf)(.222dxxfa)(22dxxaf)(.322dxxfa)(22dxaxf)(.422dxafx)(22taxsintaxcos或taxsectaxcsc或taxtantaxcot或0.)(122adxaxdxasec2tdt,taxtanxadx221tdtsec1tanlnsecCtt122lnCaaxaxaxt.ln22Caxx,22ttdttaasec2sec10).(122aadxxasect,x2,0tadxx221Ctttanseclntax,tansectdttadxsectdtdttattatantansecCaaxax22ln.ln22Caxx,(1)22axasint;x,2)(22axatant;xxasect.,3)(22xa()Cxxdx|ln|costanCxxdx|ln|sincotCxxxdx|tanln|secsecCxxxdx|cotln|csccscCaxaxdxa1arctan122(16)(17)(18)(19)(20)(21)Caxaxaadxx2ln1122(22)Caxxdxaarcsin122(23).ln12222Caxxadxx0).(022xdxaaaxasint,tdtadxcos22xaaxdxa0222022costdta2022cos21tdta202cos2)(12tdta2022sin212tta.4a2xt/2a00ta1sin2acost,0).(022xdxaaaaxdxa022.4a2222ayx.[,]a0..a0..-adtePt1000147200.).(..tdet014014720001001438756102466541285).(.dteAt10001435000.A).(..tdeAt014140010014)(..014101410eAA6504(元)t=0tArtAea][,tttattertat=0.dtaePTrt0tT[0,T]td(rt)eraTrt0d(rt)eraTrt00Trerta)(erTra1)(.)(..5万美元4173012160001215ePra