My table of Integrals has the final scenario ##int frac dx x^2+a^2 ## being a 'common' integral also, not just the situation where by ##a=1##. But I feel this becoming a Calculus research trouble it is anticipated in the OP to determine how to get it done. Hints got previously https://gabletoppak.com/india-emerges-as-the-largest-plastic-polluter-globally/