Integration question relating to inverse trig functions.

Hi,

I've been doing some differentiation of inverse trig. In doing this I had to find the derivative of:

$\displaystyle

arctan (3x/2)$

I found this to be: $\displaystyle 6/(9x^2 + 4)$

To check this answer I thought I would try to integrate to see if I arrived back at the original question. However, I'm a bit stumped as to how I should go about integrating it?

I know that the original derivative was derived using the chain rule so is there some substitution that I can use to find the integral of $\displaystyle 6/(9x^2 + 4)$

Thanks,