My desk of Integrals has the overall case ##int frac dx x^2+a^2 ## like a 'typical' integral also, not simply the situation in which ##a=one##. But I do think this currently being a Calculus homework problem it is anticipated on the OP to determine how to make it happen. Hints https://gabletoppak.com/a-revolutionary-step-towards-sustainable-water-bottle-packaging/