I'm trying to do a problem that is integration by parts.

$\displaystyle \int {x}^{3}{e}^{{x}^{2}}/{({x}^{2}+1)}^{2} dx$

I'm pretty sure I need to do a substitution, like make $\displaystyle g={x}^{2}$ but I'm not sure.

If that is the case, I'm not sure where to go next. What should be my u and what should be my dv?

Thanks,

MJ