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IntegrationbyParts–TABULARMETHOD--PaulkNotesPage 1
SOURCE:http://pages.pacificcoast.net/~cazelais/187/tabular.pdf
IntegrationbyParts–TABULARMETHOD--PaulkNotesPage 2AdditionalcommentsbyKathyPaulk:
• Normally,wedecidewhichpartwillbeDIFFERENTIATEDbytheorder“LIATE”whichstandsfor:• Logs,InverseFunctions,Algebra,Trig,Exponents.Thishelpsustochoosethedifferentiatedpartthatismorelikelytoreducetozero.• IftheDsideisalogfunction ln 𝑥 ,thenwestopafteronestep !
!
• IftheDsidedoesnotreducetozero,thenwelookfortheproducttoaequalamultiple 𝑛 ∗ 𝐼 oftheoriginalintegral 𝐼 .• NOTE:HorizontalarrowèGiveup/STOPèTaketheintegraloftheproduct• NOTE:Giveup/STOPwhenDsidedoesnotreducetozeroororiginalintegralisamultipletheproductofD*I.(repeating)
LookingatExample#4inmoredetail:
• ThesourceoftheexampledidnotfollowtheLIATErecommendation.Instead,the“exponent”partwaschosentobedifferentiated.• Note,thatthetabularmethodworks,regardlessofwhichpartischosentobedifferentiated.
𝐼 = 𝑒!! cos 𝑥 𝑑𝑥
𝐼 = 𝑒!! (sin 𝑥 )− 2𝑒!! − cos 𝑥 + 4𝑒!! − cos 𝑥 𝑑𝑥
𝐼 = 𝑒!! (sin 𝑥 )+ 2𝑒!! cos 𝑥 − 4 4𝑒!! cos 𝑥 𝑑𝑥
𝐼 = 𝑒!! (sin 𝑥 )+ 2𝑒!! cos 𝑥 − 4 𝐼
5𝐼 = 𝑒!! (sin 𝑥 )+ 2𝑒!! cos 𝑥
𝐼 = !!!
!sin 𝑥 + 2 cos 𝑥
𝐼 = 𝑒!! cos 𝑥 𝑑𝑥
usingLIATErule… 𝐼 = cos 𝑥 !
!𝑒!! + sin 𝑥 !
!𝑒!! + (− cos 𝑥) !
! 𝑒!! 𝑑𝑥
𝐼 = cos 𝑥 !!𝑒!! + sin 𝑥 !
!𝑒!! − !
! cos 𝑥 𝑒!! 𝑑𝑥
𝐼 = cos 𝑥 !!𝑒!! + sin 𝑥 !
!𝑒!! − !
! 𝐼
!!
𝐼 = cos 𝑥 !!𝑒!! + sin 𝑥 !
!𝑒!!
𝐼 = !!
cos 𝑥 !!𝑒!! + !
! sin 𝑥 !
!𝑒!!
𝐼 = !!
cos 𝑥 𝑒!! + !!
sin 𝑥 𝑒!!
𝐼 = !!!
! 2 cos 𝑥 + sin 𝑥 Sameanswer!
D I
𝑒!! + cos𝑥
2𝑒!! − sin 𝑥
4𝑒!! + − cos 𝑥
D I
cos𝑥 + 𝑒!!
− sin 𝑥− !!𝑒!!
− cos𝑥 + !!𝑒!!