My Table of Integrals has the final circumstance ##int frac dx x^2+a^2 ## being a 'normal' integral much too, not just the case exactly where ##a=one##. But I do think this becoming a Calculus homework challenge it is anticipated of the OP to figure out how to make it happen. https://gabletoppak.com/how-white-labelled-water-elevated-business-image/