My table of Integrals has the overall situation ##int frac dx x^two+a^2 ## as a 'conventional' integral also, not simply the case wherever ##a=1##. But I believe this becoming a Calculus research challenge it is expected with the OP to determine how to make it happen. Hints were given above. https://gabletoppak.com/how-gable-top-pak-can-enhance-your-brand-and-customer-experience/