My table of Integrals has the general situation ##int frac dx x^2+a^2 ## for a 'regular' integral way too, not simply the situation exactly where ##a=1##. But I believe this currently being a Calculus research challenge it is predicted of the OP to figure out how to do it. Hints https://gabletoppak.com/the-growing-threat-of-marine-pollution-and-how-gabletop-cartons-offer-a-solution/