you could try the substitution
x =3 cosh(u) if you know about hyperbolic functions
I'm having a little trouble solving this integral.
Its kinda hard to do it without the symbols but i'll try my best.
~ dx / (x^2 -9) ^ (3/2)
Now I know the (3/2) power would make the denominator:
dx / square root ( (x^2 - 9 ) ^ 3)
I'm just not entirely sure where to head from there. Any suggestions?