I've been struggling with integration by parts. Can anyone explain these problems to me?

http://hosted2.webwork.rochester.edu...361817ca91.png

http://hosted2.webwork.rochester.edu...e3b5345091.png

Help is very much appreciated. Thank you!

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- Nov 9th 2009, 05:27 PMKimmy2Integration by Parts problem
I've been struggling with integration by parts. Can anyone explain these problems to me?

http://hosted2.webwork.rochester.edu...361817ca91.png

http://hosted2.webwork.rochester.edu...e3b5345091.png

Help is very much appreciated. Thank you! - Nov 9th 2009, 05:32 PMProve It
- Nov 9th 2009, 05:36 PMBERRY
For the second problem, set and

- Nov 9th 2009, 06:19 PMKimmy2
So, I have:

u=t

du=dx

dv=e^-t

v= -e^(-t)

And then:

-te^(-t) - the integral from 6 to 0 of -e^(-t)dx

And then if I take the integral of -e^-tdx, I get -ln(e^-t)?

Is this okay, so far? - Nov 9th 2009, 06:54 PMBERRY
- Nov 9th 2009, 08:04 PMKimmy2
So, after I plug in all the u and v values, I'm getting:

t(-e^-t) - the integral of -e^(-t)

Once I integrate that last part, I'm getting:

t(-e^-t) - e^(-t)

Is this right? - Nov 9th 2009, 08:32 PMBERRY
Yes that is correct. Just plug in the bounds now.

- Nov 9th 2009, 08:38 PMKimmy2
I have plugged in the numbers multiple times, and my homework keeps telling me that I'm wrong. :(

Some of the answers I got were:

-0.1983001 and 1.01239376

EDIT!

I got it, thanks so much for your help!! - Nov 9th 2009, 08:51 PMProve It