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Homework Help: Please help me integrate homework

  1. Aug 9, 2008 #1
    Please help me integrate homework :(

    [/tex]1. The problem statement, all variables and given/known data



    2. Relevant equations
    \int dx/(1-x^2)^3

    3. The attempt at a solution

    I believe I have to use partial fractions to solve this integral. I started out by expanding the denominator

    1/-(1 - 3x^2 + 3x^4 - x^6)

    I pulled out a negative then separated by polynomial

    x^4 (x^2 + 3) - 3(x^2 + 3) - 8

    so:
    -(x^4 - 3)(x^2 + 3) - 8

    I'm lost..I need help
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Aug 9, 2008 #2

    HallsofIvy

    User Avatar
    Science Advisor

    Re: Please help me integrate homework :(

    Why in the world would you expand it? You want to factor it. It is already partly factored, don't throw that away! 1- x2= (1- x)(1+ x) so
    (1-x2)3= (1- x)3(1+ x)3

    [tex]\frac{1}{(1- x^2)^3}= \frac{A}{1-x}+ \frac{B}{(1-x)^2}+ \frac{C}{(1- x)^3}+ \frac{D}{1+ x}+ \frac{E}{(1+x)^2}+ \frac{F}{(1+x)^3}[/tex]

     
  4. Aug 9, 2008 #3
    Re: Please help me integrate homework :(

    Thank You! I know I can solve it now!
     
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