My desk of Integrals has the final case ##int frac dx x^2+a^2 ## being a 'conventional' integral as well, not only the situation wherever ##a=one##. But I do think this becoming a Calculus homework dilemma it is predicted of your OP to determine how to do it. Hints were given https://gabletoppak.com/sustainable-liquid-soap-packaging-why-gabletop-cartons-are-the-eco-friendly-choice/