My desk of Integrals has the general situation ##int frac dx x^2+a^2 ## for a 'conventional' integral as well, not only the case in which ##a=1##. But I believe this currently being a Calculus research challenge it is predicted with the OP to figure out how to get it done. https://gabletoppak.com/lakes-developed-under-smart-cities-initiative-in-coimbatore-turn-dumping-grounds-for-plastic-waste/