My desk of Integrals has the final circumstance ##int frac dx x^two+a^two ## to be a 'standard' integral as well, not only the case in which ##a=1##. But I think this getting a Calculus homework difficulty it is expected in the OP to figure out how to do it. Hints https://gabletoppak.com/travel-green-gabletop-paks-sustainable-shift/