Real Variable Function

This textbook connects the problems in real variable functions with the calculus content they have learned, allowing students to understand that all problems have their origins and origins, stimulating learning motivation and interest; it also introduces subject areas related to real variable functions, allowing students to understand the applications of real variable functions. Secondly, it emphasizes the use of geometric intuition to understand concepts and theorems as much as possible. The book is equipped with some illustrations to transform abstract concepts and theorems into intuitive and tangible things as much as possible. In particular, the connections between the contents are explained and explained from as many aspects as possible. In addition, this book is equipped with a large number of exercises, divided into two parts: basic questions and difficult questions. As a basic requirement for teaching, students are only required to complete the basic questions. The puzzle sections are for mobile use and are encouraged to be studied by some students who have the ability and time.