My desk of Integrals has the overall case ##int frac dx x^two+a^2 ## to be a 'typical' integral way too, not just the situation in which ##a=one##. But I believe this remaining a Calculus homework problem it is anticipated of the OP to determine how to do it. Hints were https://gabletoppak.com/lakes-developed-under-smart-cities-initiative-in-coimbatore-turn-dumping-grounds-for-plastic-waste/