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Parital fractions?

  1. Nov 7, 2006 #1
    I have never remebered the different partial fraction forumlas. Is there a way to decide which partial fraction formula to use just by looking at the expression?
  2. jcsd
  3. Nov 7, 2006 #2


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    Partial fraction formulae?

    I thought you just did partial fractions... what's the context? Normally you just split the fraction after factoring the denominator into a sum of fractions with denominators equal to the different factored parts
  4. Nov 7, 2006 #3


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    over R, the only prime polynomials are linear or quadratic. the numerators are either constant or linear respectively.

    if f^n is a factor of the denominator, where f is prime, we need to allow for all fractions whose greatest common denom is f^r, so we have

    to allow a/f , b/f^2, c/f^3, ...., d/f^n, for appropriate numerators.

    e.g. to decom,pose h/[x^2(x^2+x+1)^3] we set it equal to

    a/x + b/x^2 + (cx+d)/(x^2+x+1) +(ex+f)/(x^2+x+1)^2 + (gx+h)/(x^2+x+1)^3.

    where a,b,c,d,e,f,g,h, are constants.
    Last edited: Nov 7, 2006
  5. Nov 8, 2006 #4
    Is that all there is to partial fractions? It isn't as mystifying as it appears.
  6. Nov 8, 2006 #5


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    Yes it is! :smile:
    No, it isn't! :smile:
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