Just needed a bit of confirmation that I was doing this problem correctly. I started off using a table definition that you can see at the bottom of that picture. The part that got cut off just shows: u/a^2sqrt(u^2+a^2). After that I just put in 0 and infinity, and came out with the constants * 1/r^2. Does that seem like an appropriate answer?
Link: imgur: the simple image sharer
Thanks for the reassurance, I got that answer using the tables definition and when I went to evaluate, I got the right part of that (the non-limit part) equaling zero. However, the limit part i'm confused with. The top part is infinity and so is the bottom it would seem. I used LHopitals Rule, but it seemed to keep on going forever because the bottom always equaled infinity which would make this problem 0-0=0....and that does not seem correct given that this is a physics formula and usually would have an answer greater than 0.
Thanks again for the quick response!