My Table of Integrals has the overall scenario ##int frac dx x^2+a^2 ## for a 'normal' integral much too, not simply the situation where by ##a=1##. But I feel this currently being a Calculus homework challenge it is expected of the OP to determine how to get it done. Hints https://gabletoppak.com/how-gable-top-pak-can-enhance-your-brand-and-customer-experience/