It's a physics course without physics, if that makes any sense. To answer the question though, complex analysis is a part of the course rather then a prerequisite (e.g. it includes the most basic proofs/definitions for differention of functions of a complex variable).
I do recall seeing the...
The textbook used in one of my courses talks about expanding functions in powers of 1/z aka negative powers of z.
The problem is that I cannot recall that any previous course taught me/challenged me on how to expand functions in negative powers. For example, Taylor series only have positive...