My table of Integrals has the final situation ##int frac dx x^two+a^two ## being a 'regular' integral as well, not only the case in which ##a=one##. But I think this staying a Calculus research difficulty it is expected from the OP to figure out how to make it happen. Hints https://gabletoppak.com/beyond-beverages-gable-top-cartons-the-versatile-customized-packaging-solution/