My Desk of Integrals has the overall case ##int frac dx x^two+a^two ## as being a 'conventional' integral way too, not merely the situation in which ##a=one##. But I feel this remaining a Calculus research difficulty it is anticipated of the OP to determine how to make it happen. Hints https://gabletoppak.com/glass-bottles-for-beer-soda-and-even-water-found-to-contain-toxic-levels-of-cancer-linked-microplastics-than-plastic-bottles-study-says/