if anyone can help me with this, that would be great!

this is from ln3 to ln2

∫ 3/(e^(3t)) dt=???

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- Mar 23rd 2010, 06:44 PMgearshifterdefinite integrals
if anyone can help me with this, that would be great!

this is from ln3 to ln2

∫ 3/(e^(3t)) dt=??? - Mar 23rd 2010, 06:58 PMdedust
- Mar 24th 2010, 11:41 AMgearshifter
what do I do with the 3 on top?

- Mar 24th 2010, 11:57 AMharish21
If you are not getting what the above post says:

let $\displaystyle u = 3t$

then, $\displaystyle du = 3 dt $

so,$\displaystyle dt= \frac{du}{3}$

so you have

$\displaystyle \int_{ln3}^{ln2} {3 e^{-u}}\frac{du}{3} $

= $\displaystyle [-e^{-u}]_{ln3}^{ln2} $

substitute u = 3t, you get

$\displaystyle [-e^{-3t}]_{ln3}^{ln2}$

calculate the value for the given upper and lower limits