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duki
May6-08, 08:29 PM
1. The problem statement, all variables and given/known data

\int\sin(6\theta) d\theta


2. Relevant equations



3. The attempt at a solution

\int6\cos6\theta

Am I close?

Feldoh
May6-08, 08:35 PM
If it helps do a u-sub where u=6theta

Or you could think of it like this:

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

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

So from there it's easy to see that\int\sin(6\theta) d\theta = \frac{-cos(6\theta)}{6}

duki
May6-08, 08:36 PM
errr...

\frac{-\cos6\theta}{6}

duki
May6-08, 08:36 PM
thanks :)

Feldoh
May6-08, 08:37 PM
Yeah looks right^^