My table of Integrals has the final scenario ##int frac dx x^2+a^2 ## for a 'typical' integral also, not just the situation where by ##a=one##. But I do think this staying a Calculus homework trouble it is anticipated with the OP to figure out how to do it. Hints were https://gabletoppak.com/how-white-labelled-water-elevated-business-image/