Hey

Im stuck on the last step of another trig sub again...

Heres the problem: integrate 1/((x^2)*(sqrt(4x^2-9))

I've sub'd x=3/2sec(theta)

I get to the point after integrating ..(2sin(theta))/9 and have to sub back in for theta

I realise theta=sec^-1(2x/3) but do not understand how i can use 2(sin(sec^-1(2x/3))/9 to finish the problem.

Please help =)

thanks