Hello, I just have two problems. I have used integration by parts, but I get stuck. The work you show will be greatly appreciated.

Thanks!

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- Jan 23rd 2009, 04:37 PMMr. EngineerIntegration by Parts
Hello, I just have two problems. I have used integration by parts, but I get stuck. The work you show will be greatly appreciated.

Thanks! - Jan 23rd 2009, 04:48 PMMush
- Jan 23rd 2009, 04:50 PMMr. Engineer
no, its the way it is, i trued just using u-substitution, but the answer was not what I got, we were supposed to use integration by parts to solve that one

- Jan 23rd 2009, 04:57 PMTKHunny
- Jan 23rd 2009, 05:17 PMgalactus
Do you have to use parts?. I think a sub is easier.

Now, let

Make the subs and we get:

Now, let's use tabular integration:

This works well when we have a something such as e or sin that repeats as we take derivatives. It's based off parts, though. So, I reckon we are using parts.(Giggle)

Add up the signed products diagonally and alternate signs.

Resub:

Someone will come by saying, "this way is easier". Oh well. I wanted to show you tabular integration in the event you have not seen it. The more one knows the better. - Jan 23rd 2009, 05:34 PMJhevon
incidentally, a substitution works nicely with the first one also

Let , that is,

So our integral becomes

which is easy to do by parts. you can also use the tabular method as galactus showed you, but it would be overkill here, i think - Jan 23rd 2009, 05:34 PMDeMath
(Giggle)