My desk of Integrals has the overall case ##int frac dx x^2+a^2 ## as a 'regular' integral far too, not just the case where by ##a=one##. But I do think this remaining a Calculus homework problem it is anticipated from the OP to determine how to do it. Hints were https://gabletoppak.com/best-alternatives-to-plastic-water-bottles-in-kerala-for-a-greener-future/