My table of Integrals has the general case ##int frac dx x^2+a^2 ## like a 'conventional' integral far too, not merely the case the place ##a=one##. But I do think this currently being a Calculus research problem it is expected from the OP to figure out how to do it. https://gabletoppak.com/why-gabletop-cartons-outshine-pet-bottles-for-branding-opportunities/