My table of Integrals has the general scenario ##int frac dx x^2+a^two ## as being a 'standard' integral way too, not simply the case where ##a=one##. But I believe this being a Calculus homework challenge it is expected with the OP to determine how to get it done. Hints got https://gabletoppak.com/choosing-between-gable-top-packaging-and-plastic-bottles-for-your-beverage-business/