After getting the constants A and B It can be reasonably easy to compute the integral ##int frac dx x^two + 9 ## as it can now be penned as two less complicated integrals. I tried but I simply cannot see how ##A,B## are constants? The article traces the background https://gabletoppak.com/gabletop-pak-leading-the-way-as-milk-carton-manufacturers-in-india/