My table of Integrals has the final scenario ##int frac dx x^two+a^2 ## as being a 'regular' integral much too, not just the case wherever ##a=one##. But I feel this getting a Calculus research problem it is predicted of the OP to determine how to get it done. Hints were https://gabletoppak.com/single-use-plastic-water-bottles-will-not-be-available-in-himachal-from-june-1-use-glass-bottles-and-dispensers-instead/