http://img24.imageshack.us/img24/1061/ahhr.jpg

Hello. I need help learning how to do this. I actually undersrtand everything except why these2are appearing.

Can anyone explain to me why they appear on these (f)avg equations?

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- Jul 20th 2009, 08:48 PMazurephantomf(avg) why are 2s appearing?
http://img24.imageshack.us/img24/1061/ahhr.jpg

Hello. I need help learning how to do this. I actually undersrtand everything except why these**2**are appearing.

Can anyone explain to me why they appear on these (f)avg equations? - Jul 20th 2009, 08:56 PMjanvdl
I only took a quick look at it, but it would appear that when you substitute (-3) and subtract it, you actually get the same term as when you substitute (+3). (Symmetric function?)

So you actually have this:

$\displaystyle 2 \times \frac{1}{6} \left[ \frac{x^3}{3} + 7x \right] ^{3} _{-3}$ - Jul 20th 2009, 09:30 PMazurephantom
Oh now I understand. This is really help me speed through some problems.

- Jul 21st 2009, 01:08 AMmr fantastic
- Jul 21st 2009, 01:14 AMMoo
Actually, the way it's done, it would rather be :

Since $\displaystyle g(x)=\frac{x^3}{3}+7x$ is an odd function, then $\displaystyle \left[\frac{x^3}{3}+7x\right]_{-3}^3=g(3)-g(-3)=2g(3)$