My table of Integrals has the final circumstance ##int frac dx x^two+a^2 ## like a 'common' integral too, not simply the case where ##a=one##. But I do think this becoming a Calculus research dilemma it is anticipated on the OP to figure out how to make it happen. Hints got https://gabletoppak.com/supporting-sdg-14-life-below-water-through-sustainable-edible-oil-packaging-with-gabletop-cartons/