My Table of Integrals has the final case ##int frac dx x^2+a^2 ## being a 'conventional' integral much too, not simply the case exactly where ##a=1##. But I do think this staying a Calculus homework issue it is predicted with the OP to figure out how to get it done. https://gabletoppak.com/india-leads-in-generating-plastic-waste-with-10-2-mn-tonnes-a-year-study/