My table of Integrals has the overall scenario ##int frac dx x^two+a^two ## to be a 'standard' integral as well, not only the case where by ##a=one##. But I do think this being a Calculus homework difficulty it is predicted from the OP to figure out how to get it https://gabletoppak.com/why-white-label-water-bottles-are-a-game-changer-for-your-brand/