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