# Calculus

posted by
**Anonymous**
.

integral -oo, oo [(2x)/(x^2+1)^2] dx

(a) state why the integral is improper or involves improper integral

*infinite limit of integration

(b) determine whether the integral converges or diverges

converges?

(c) evaluate the integral if it converges

I know f(x)=arctan->f'(x)=1/(1+x^2)

I'm not sure what I do with the 2x in the numerator and the squared demoninator.