I attempted this and got nowhere (see attached work if you want). I then used Wolfram Alpha to see how to do it and that tanh stuff is something I have to see. Of course, I've heard of it from my previous teacher but, I have never actually covered it in a course. Furthermore, my teacher does not expect me to use such a method (I'm assuming), so I was hoping someone could help me figure this out using substitution or something of the sort. (I have not learned integration by parts for instance)
Wolfram Alpha's "work": http://www.wolframalpha.com/input/?i=integral+4%2F(x^2+-+1)
Any help would be greatly appreciated!
Thanks in advance!