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Homework Help: Integrating Sin

  1. May 6, 2008 #1
    1. The problem statement, all variables and given/known data

    [tex]\int\sin(6\theta) d\theta[/tex]


    2. Relevant equations



    3. The attempt at a solution

    [tex]\int6\cos6\theta[/tex]

    Am I close?
     
  2. jcsd
  3. May 6, 2008 #2
    If it helps do a u-sub where u=6theta

    Or you could think of it like this:

    If we take the derivative of [tex]\frac{d}{d \theta}(-cos(\theta)) = sin(\theta)[/tex]. That's sort of like the anti-derivative which you seek.

    If we take the derivative of [tex]\frac{d}{d \theta}(-cos(6 \theta)) = 6sin(6 \theta)[/tex].

    So from there it's easy to see that[tex]\int\sin(6\theta) d\theta = \frac{-cos(6\theta)}{6}[/tex]
     
  4. May 6, 2008 #3
    errr...

    [tex]\frac{-\cos6\theta}{6}[/tex]
     
  5. May 6, 2008 #4
    thanks :)
     
  6. May 6, 2008 #5
    Yeah looks right^^
     
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