My table of Integrals has the overall scenario ##int frac dx x^two+a^two ## as a 'regular' integral way too, not simply the situation where by ##a=one##. But I do think this being a Calculus homework issue it is expected in the OP to figure out how to get it done. https://gabletoppak.com/india-leads-in-generating-plastic-waste-with-10-2-mn-tonnes-a-year-study/