My table of Integrals has the overall scenario ##int frac dx x^2+a^2 ## to be a 'regular' integral too, not merely the situation in which ##a=one##. But I believe this being a Calculus homework problem it is expected on the OP to determine how to do it. Hints got above. https://gabletoppak.com/water-in-a-sustainable-box-the-future-of-eco-friendly-hydration/