My Table of Integrals has the general case ##int frac dx x^2+a^2 ## to be a 'regular' integral far too, not just the case the place ##a=one##. But I think this becoming a Calculus homework difficulty it is anticipated in the OP to figure out how to get it done. https://gabletoppak.com/how-gable-top-pak-can-enhance-your-brand-and-customer-experience/