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p3 intergration question watch

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    its q20 in the heinemain p3 REVISION book, in the intergration section:

    prove that: { (x^2+4) / (x^2 - 4) dx = 1 +2ln(5/3)

    between 4 and 3



    i used partial fractions then intergrated, and got:

    x + 8ln(x^2 -4)


    is this correct?????????????????????????

    thx in advance
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    (Original post by Asha)
    its q20 in the heinemain p3 REVISION book, in the intergration section:

    prove that: { (x^2+4) / (x^2 - 4) dx = 1 +2ln(5/3)

    between 4 and 3



    i used partial fractions then intergrated, and got:

    x + 8ln(x^2 -4)


    is this correct?????????????????????????

    thx in advance
    I got ln[2r7r9]
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    (Original post by Asha)
    its q20 in the heinemain p3 REVISION book, in the intergration section:

    prove that: { (x^2+4) / (x^2 - 4) dx = 1 +2ln(5/3)

    between 4 and 3



    i used partial fractions then intergrated, and got:

    x + 8ln(x^2 -4)


    is this correct?????????????????????????

    thx in advance
    No, since you've integrated 1/(x^2-4) to ln x^2 -4, which isn't right, try differentiating ln x^2-4.

    Now we have x^2+4/x^2 -4 = 1 + 8/x^2-4. Now write x^2-4 = (x+2)(x-2), split 8/(x+2)(x-2) into partial fractions and then integrate.
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    thanks people,
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    (Original post by Bhaal85)
    I got ln[2r7r9]
    Dont know where the 1 comes from.

    2ln(5/3) = ln[2r7r9]
 
 
 
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