integration by parts: int [cot^(-1)(3x)] dx

[AhItsCalculus]

I don't know how to solve this problem using integration by parts :/
S-(intergral symbol)
S cot^-1 3x dx

 

[galactus]

Let \(\displaystyle \L\\u=cot^{-1}(3x), \;\ dv=dx, \;\ du=\frac{-3}{9x^{2}+1}dx, \;\ v=x\)

\(\displaystyle \L\\xcot^{-1}(3x)+\int\frac{3x}{9x^{2}+1}dx\)

Finish?.