My table of Integrals has the general case ##int frac dx x^2+a^2 ## being a 'conventional' integral too, not just the case the place ##a=one##. But I feel this staying a Calculus research challenge it is expected of the OP to figure out how to do it. Hints got over. https://gabletoppak.com/india-leads-in-generating-plastic-waste-with-10-2-mn-tonnes-a-year-study/