My desk of Integrals has the overall scenario ##int frac dx x^two+a^two ## for a 'conventional' integral too, not just the case exactly where ##a=1##. But I think this getting a Calculus homework difficulty it is anticipated in the OP to figure out how to do it. Hints were given https://gabletoppak.com/sustainable-liquid-soap-packaging-why-gabletop-cartons-are-the-eco-friendly-choice/