My desk of Integrals has the final situation ##int frac dx x^two+a^2 ## for a 'typical' integral also, not just the situation in which ##a=1##. But I feel this being a Calculus research trouble it is expected of your OP to determine how to make it happen. Hints got over. https://gabletoppak.com/is-it-legal-to-sell-natural-mineral-water-in-gabletop-cartons-tetra-paks-and-aluminium-cans-in-india/