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Indefinite integral help

  1. Jan 18, 2008 #1
    How can I evaluate [itex]\int\frac{dx}{\sqrt{1-2x-x^2}}[/itex] using inverse trig functions? Thanks.
  2. jcsd
  3. Jan 18, 2008 #2


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    complete the square of the quadratic.
  4. Jan 18, 2008 #3
    Oh... thanks.

    Dang these are so hard... I wish I had the creativity to see the solution immediately like that...
  5. Jan 18, 2008 #4
    ax^2+bx+c, a=1, factor out the negative before you complete the square if you didn't remember.
  6. Jan 18, 2008 #5
    Thanks. I got the right answer after rock.freak667's hint. I just wish I were able to solve these more easily, without hints from this forum and elsewhere.... does it just take lots of practice, or what?
  7. Jan 18, 2008 #6
    Read read read! And do the practice problems :-]

    Go here to see a variety of diff. methods.

    http://www.mathlinks.ro/weblog_entry.php?p=992552#992552 [Broken]
    http://www.mathlinks.ro/weblog_entry.php?p=992575#992575 [Broken]
    http://www.mathlinks.ro/weblog_entry.php?p=992703#992703 [Broken]
    Last edited by a moderator: May 3, 2017
  8. Jan 18, 2008 #7

    Gib Z

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    When it comes to integrals, its experience that really counts. Do as many integrals as you can, you'll soon learn the tricks of the trade.
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