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Idiot check my integration

Teslan26Teslan26 Registered User regular
edited March 2010 in Help / Advice Forum
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Posts

  • Teslan26Teslan26 Registered User regular
    edited February 2010
  • musanmanmusanman Registered User regular
    edited February 2010
    not sure why your quantity is still squared in the middle step after you expanded the binomial

    musanman on
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  • SanderJKSanderJK Crocodylus Pontifex Sinterklasicus Madrid, 3000 ADRegistered User regular
    edited February 2010
    It seems correct. Note that it simplifies significantly if you actually enter the 2pi at the end. (All parts become constant*pi^5)
    musanman wrote: »
    not sure why your quantity is still squared in the middle step after you expanded the binomial
    True, those shouldn't be there.

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  • Teslan26Teslan26 Registered User regular
    edited February 2010
    SanderJK wrote: »
    It seems correct. Note that it simplifies significantly if you actually enter the 2pi at the end. (All parts become constant*pi^5)

    Aye - yet it gives me the wrong answer. Guess I am screwing up somewhere further along the line. Ah well. Hand it in and let the Gods decide.

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  • tinwhiskerstinwhiskers Registered User regular
    edited February 2010
    I haven't done calc in a couple years, but shouldn't you have a negative sign before (your answer) since you are integrating from 2pi to 0, not 0 to 2pi.

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  • mspencermspencer PAX [ENFORCER] Council Bluffs, IARegistered User regular
    edited March 2010
    If it helps, my TI-89 simplifies your definite integral to: -16*pi^5/15

    So you expanded the polynomial correctly (not counting the extra ^2 which you meant to remove) and you integrated them correctly. Now all you need to do is find a value for that expression at theta=0, find a value of the expression at theta=2pi, and subtract.

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  • DemerdarDemerdar Registered User regular
    edited March 2010
    Yeah, you might be messing up when you plug in your limits of integration.

    Also check out the integrator:
    http://integrals.wolfram.com/index.jsp

    This is a good tool to double check your indefinite integrals.

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