Doing the following integral

I haven't done basic integrals for awhile...but just wondering how you would integrate the following functions without looking it up in the integral table.

(x^2+a^2)^(-3/2) where a is a constant.

Thanks!

Make the substitution $x=a\sinh t$ and then see what you get.
The substitution $x= atan(\theta)$ will also work.