ABSTRACT
This chapter provides a very brief summary of work on generalized trigonometric functions and related topics. We do not seek completeness in terms of all the various formulations and results which have appeared in the scientific and mathematical research literature. Upon examining these works, it becomes clear that there is not full unity with regard to the definition of the generalized sine and cosine functions. This is also demonstrated in the present work of the author within this book. Consequently, the main task of the chapter is to introduce and summarize some of the publications that have influenced my views of generalized trigonometric functions.
