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Homework Help: Surface area of sin(x) rotated about the x-axis

  1. Feb 21, 2012 #1
    got stuck on doing the substitution.. any suggestions?
     

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  2. jcsd
  3. Feb 21, 2012 #2

    SammyS

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    For one thing, the derivative of 1 + cos2(x) is -2sin(x)cos(x), not -2sin(x).

    That substitution doesn't seem to help anyway.

    Try u = cos(x) instead.
     
  4. Feb 21, 2012 #3
    wow, i did not see that.
    thanks so much!
     
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