My table of Integrals has the overall situation ##int frac dx x^2+a^2 ## as a 'regular' integral as well, not just the situation where by ##a=one##. But I feel this currently being a Calculus homework issue it is expected of the OP to determine how to get it done. Hints https://gabletoppak.com/is-it-legal-to-sell-natural-mineral-water-in-gabletop-cartons-tetra-paks-and-aluminium-cans-in-india/