ABSTRACT
This chapter is a self-contained review of some basics of the differential calculus of several variables. We assume that you are fairly familiar with these results and just need to browse through this chapter to get familiar with some standard notation/results to be used in the rest of the book. However, if you are learning some of them for the first time, you may need to go through it slowly. In any case, whenever you have some difficulty in later chapters, often it just helps to come back to this chapter for the relevant clarification.
