My Table of Integrals has the overall scenario ##int frac dx x^2+a^2 ## like a 'standard' integral way too, not merely the case in which ##a=1##. But I think this being a Calculus homework difficulty it is anticipated in the OP to figure out how to make it happen. Hints https://gabletoppak.com/why-gabletop-cartons-outshine-pet-bottles-for-branding-opportunities/