My Desk of Integrals has the general situation ##int frac dx x^2+a^2 ## being a 'common' integral way too, not only the case where by ##a=one##. But I feel this getting a Calculus research issue it is anticipated of the OP to determine how to make it happen. Hints got https://gabletoppak.com/from-plastic-bottles-to-gabletop-cartons-a-step-toward-solving-the-plastic-pollution-crisis/