A complicated integral

[ARYT]

1. The problem statement, all variables and given/known data

My answer should not be correct. Right?:uhh:
Refer to the attachment please.

2. Relevant equations

Refer to the attachment please.

3. The attempt at a solution

Refer to the attachment please.

Cheers

[Count Iblis]

Why not do a partial integration?

x/sqrt[x^2+1] * x^2 dx

You can integrate x/sqrt[x^2+1] this is proportional to
sqrt[x^2+1]

So, if you do a partial integration, you'll have to deal with the integral:

x sqrt[x^2+1]

where the x comes from the derivative of x^2. But this is then proportional to (x^2+1)^(3/2).