Did you cover double integrals?
Hey I am new to this site but I was wondering what software you are using to display the integrals.
I looked at the problem and was going to propose a direction to try. If you do integration by parts you get u=arctan(x) dv= 1/ln(1+t)
I was thinking that 1/ln(1+t) might be a workable integral. What calculus level are you taking?