A combined maths Q

Lalakajee

Well-known member
  • Jun 20, 2007
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    In my own heart
    kotas washayen anukalanaya karanna puluwan neda??:confused: Sure nehe:(

    http://en.wikipedia.org/wiki/Integration_by_parts

    http://community.boredofstudies.org/showthread.php/167635-Integration?p=3316947:D

    http://in.answers.yahoo.com/question/index?qid=20080220024624AAoHR5q
    me link eke mehema heduwa!!!:shocked:
    I=∫ log(sin x).dx .............eq 1
    I=∫logsin(π/2-x)dx
    I=∫logcosx dx.......................eq2
    add1&2
    2I=∫logsinx+logcosx dx
    =∫logsinx*cosx dx
    =∫log(sin2x)/2 dx
    =∫[logsin2x-log2] dx
    =∫logsin2xdx - ∫log2dx .................eq 3
    in the first integral put 2x=t
    d.w.t.x
    dx=dt/2
    where x=0,t=0 where x=π/2 ,t=π
    ∫logsint dt with limit t= o & t=π
    now
    ∫logsint dt =2 ∫log sint (dt /2 ) with limit t=0 t=π/2
    we can write above eq in "x" also
    =2 ∫log sinx (dx/2)
    put it in eq 3
    2I=2 ∫log sinx (dx/2) - ∫log2dx
    but ∫log sinx dx =I
    2I= I- ∫log2dx
    I= - ∫log2dx with limt x=0& x=π/2
    I= -π/2 log2
     
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    Lalakajee

    Well-known member
  • Jun 20, 2007
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    http://integrals.wolfram.com/index.jsp?expr=ln%28sinx%29&random=false

    MSP23021470071935115754_346


    msp23021470071935115754.gif
     
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    kasuncs

    Well-known member
  • May 21, 2007
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    Machan oke non real parts enawa ekayi karanna bari AL karana ayata.
    Mathemtica wage software ekak daagoth karalama balanna puluwan.
     

    Sachinth

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  • May 11, 2008
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    mathaka widiyatanam mehemai ban

    I=∫lnsinxdx u=lnsinx
    dv=dx
    v=x
    du=1/sinx*-cosx

    I=uv-∫vdu sammatha suthraya
    =lnsinx*x-∫x*-cosx/sinx
    =xlnsinx+∫xcotx

    ∫xcotx tath gunitha suthraya dala balanda ethakota I ta samana kotasak ei ekata I kiyala dala sulu karala I uktha karanda anukala lakuna nathiwa uththaraya ganda I ukthakaranda iri 2 k gahanda
    :D
     

    rehrumesh

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    Jun 17, 2008
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    kotas washayen anukalanaya karahan .... mata hariyatama mathaka na karana krame. depaththatama maruwen karala balahan...
     

    nagaya

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    Mar 18, 2007
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    oya samahra ln tiyena ewa AL ayata hadanna ba,apitat issara ohoma prasidda ganak tibba lnsinx wage thama mathaka ekath.samahru wena unge mood upset karanna ohoma ganan denwa,hondama wade clz eke sirgen ahala balana eka,matanm dan athin anukalanaya karanna mathaka na