my work so far:
anyways after that mess I am really not sure how to integrate this with u-substitution. If I made a mistake please let me know or some direction if I am right so far would be very helpful!! Thanks a lot!
for the integrand I'm getting
Both the top and bottom are perfect squares, so factor and simplify and let
EDIT: It might not be that simple actually, I haven't done the whole problem. You may need to make an additional substitution. Let me know if you get stuck again and I'll try to work it out.
EDIT2: you shouldn't need to sub at all for this integral. Sorry, I'm all mixed up right now.