My desk of Integrals has the overall case ##int frac dx x^2+a^2 ## for a 'standard' integral much too, not simply the case where ##a=one##. But I believe this being a Calculus research difficulty it is expected of your OP to figure out how to do it. Hints got over. https://gabletoppak.com/gabletop-pak-the-ideal-packaging-solution-for-dairy-products/