My Table of Integrals has the overall situation ##int frac dx x^two+a^2 ## like a 'typical' integral much too, not only the case in which ##a=one##. But I do think this getting a Calculus research problem it is expected in 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/