My table of Integrals has the overall scenario ##int frac dx x^2+a^2 ## like a 'common' integral much too, not only the case where ##a=1##. But I believe this staying a Calculus research problem it is expected from the OP to figure out how to do it. Hints got over. https://gabletoppak.com/beyond-beverages-gable-top-cartons-the-versatile-customized-packaging-solution/