Immediately after locating the constants A and B it's somewhat easy to compute the integral ##int frac dx x^two + nine ## as it might now be written as two less difficult integrals. I tried but I are not able to see how ##A,B## are constants? To limit the exercise https://gabletoppak.com/aseptic-tetra-pak-vs-non-aseptic-gable-top-choosing-the-right-carton-for-your-needs/