My table of Integrals has the overall case ##int frac dx x^two+a^2 ## as being a 'standard' integral too, not merely the case exactly where ##a=one##. But I think this currently being a Calculus research dilemma it is anticipated in the OP to figure out how to do it. Hints https://gabletoppak.com/glass-bottles-for-beer-soda-and-even-water-found-to-contain-toxic-levels-of-cancer-linked-microplastics-than-plastic-bottles-study-says/