[1] I graduated from automation. There are indeed complex numbers in the circuit analysis of this science, but the complex numbers involved are only the basic definitions and properties of complex numbers (such as complex power).

[2] Complex variable functions mainly include single-valued analytic functions, Riemann surface theory, residue theory, generalized analytic functions and so on. (Of course, complex functions also study multivalued functions), that is, to study the properties of functions in complex fields on the basis of complex numbers. Simply put, it is helpful for you to learn the circuit, but unfortunately it is of little help and the cost is too high.

[3] If you take more credits for complex variable functions, you should at least know the knowledge of differential calculus, integral calculus and series in higher mathematics (convergence and divergence), that is, the content of the first book of higher mathematics can be learned. Generally speaking, complex functions are easy to use. Mathematics is easy to get started, but difficult to master.