I'm stumped on these:

The integral of x^3 (1+x^2)^3/2

The integral of the square root of (x^2 - 1)dx/x^3

The integral of x^3 dx/(4-x^2)^2

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- February 12th 2009, 09:49 PMGreySweatshirt306A Few Integrals
I'm stumped on these:

The integral of x^3 (1+x^2)^3/2

The integral of the square root of (x^2 - 1)dx/x^3

The integral of x^3 dx/(4-x^2)^2 - February 12th 2009, 09:53 PMJhevon
- February 12th 2009, 10:04 PMGreySweatshirt306
Thanks for the help--but I don't see how a substitution works for either of those two problems.

- February 12th 2009, 10:39 PMJhevon
- February 17th 2009, 06:45 AMGreySweatshirt306Trig Substitution
Is there anyway to do these using a trig sub?

- February 17th 2009, 07:15 AMKrizalid
Utterly unnecessary.

1)

2)

3) - February 17th 2009, 09:47 AMGreySweatshirt306Thanks
Thanks for the help. I'm not very good at these though, could you flesh them out a bit? I really appreciate anything you can do

- February 17th 2009, 04:45 PMJhevon
- February 17th 2009, 05:35 PMGreySweatshirt306Yeah
Trig Subs are required

- February 17th 2009, 05:37 PMKrizalid
You didn't specify that from the beginning, and that's bad, pretty bad since you wasted Jhevon's time.

If you want to be helped, show at least what you've tried. - February 17th 2009, 05:53 PMGreySweatshirt306
Well let me edit that--

Trig subs are NOT required, what I meant to say is that I came to my math teacher with some of the work that Jhevon got me started on (thanks again), and he instructed me to also try to work them out using a trig substitution, so i'm back here. Sorry for the confusion