Do you have a foundation in mathematics and physical methods? Have you taken a similar course? That book is very good and complete. But reading it is a difficult and worthwhile process.

To learn math methods, you must close the book and be able to work out the exercises before counting.

Simply put, classical mathematics and physics at that level includes several parts.

One is partial differential equation, which is introduced in different books. Most of them are derived from wave, conduction and physical reality. Some books are more theoretical, saying that they are parabolic and elliptic equations.

One is Hilbert space. Engineering words are not used much. But this is the foundation of quantum mechanics. If you study science, you can do this part well.