My Table of Integrals has the overall situation ##int frac dx x^two+a^two ## as being a 'common' integral way too, not simply the situation where ##a=one##. But I do think this remaining a Calculus research dilemma it is predicted from the OP to figure out how to do it. Hints https://gabletoppak.com/is-bottled-water-a-healthy-choice/