My table of Integrals has the general situation ##int frac dx x^two+a^two ## for a 'common' integral much too, not simply the situation wherever ##a=1##. But I do think this remaining a Calculus homework challenge it is anticipated on the OP to figure out how to get it done. Hints https://gabletoppak.com/why-i-switched-to-water-in-a-sustainable-box/