I'm working through a course on PDEs right now, but find my textbook is simply miserable. It was good up until we moved past Cartesian coordinates, but now is hardly decipherable. Could someone recommend a good text that simply covers Laplace, eigenvalue, wave, and diffusion equation solutions on Cartesian, polar, and spherical coordinates? Well documented example problems are critical for me to learn properly. It seems to me that such a book must exist somewhere, but my search online has been fruitless.
Thanks in advance!