My desk of Integrals has the final circumstance ##int frac dx x^two+a^2 ## to be a 'typical' integral also, not merely the case where ##a=1##. But I think this currently being a Calculus homework challenge it is expected with the OP to figure out how to make it happen. Hints https://gabletoppak.com/is-it-legal-to-sell-natural-mineral-water-in-gabletop-cartons-tetra-paks-and-aluminium-cans-in-india/