Just After obtaining the constants A and B It is really reasonably very simple to compute the integral ##int frac dx x^2 + 9 ## as it could now be composed as two easier integrals. I attempted but I cannot see how ##A,B## are constants? The life of a roof https://gabletoppak.com/aseptic-tetra-pak-vs-non-aseptic-gable-top-choosing-the-right-carton-for-your-needs/