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Homework Help: How to find integrals like int (1-x)(x^2-4)dx

  1. Sep 20, 2005 #1
    I already know the answer to this, but would like your opinion on the quickest way to calculate integrals like these. I am finding myself evaluating similar integrals in my diffeq homework, and the method that I used (parts and partial fractions) is a mess and takes way too long (if it were to appear on a test).


  2. jcsd
  3. Sep 20, 2005 #2


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    Gold Member

    In general, partial fractions is the only way to go. In this particular case, you can split the integral up like this to do it pretty fast:
    Now you can directly compute the first two parts as logs and the last as a log by recognizing x as one quarter the derivative of the denomenator
  4. Sep 20, 2005 #3
    Well it looks like the only way to save time here is to use my TI-89 :smile:.

    Thanks for the reply Euler.
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