My Desk of Integrals has the overall case ##int frac dx x^2+a^2 ## being a 'normal' integral far too, not merely the situation where ##a=1##. But I think this becoming a Calculus homework issue it is expected in the OP to figure out how to get it done. Hints were https://gabletoppak.com/hc-issues-notice-over-plea-to-make-dwarka-plastic-free/