My desk of Integrals has the final circumstance ##int frac dx x^two+a^2 ## as a 'regular' integral as well, not just the situation where ##a=1##. But I believe this remaining a Calculus homework issue it is expected in the OP to figure out how to do it. Hints were given https://gabletoppak.com/best-alternatives-to-plastic-water-bottles-in-kerala-for-a-greener-future/