Author(s)

Zhang Yihe, Wu Xiaolan, Zheng Jiannan

Corresponding Author

Zhang Yihe

Abstract

This article provides the definition of comparison for infinite order, demonstrates several theorems of equivalent infinity, proves theorems of and other equivalent substitution for undetermined limit, and uses these theorems’ conclusions to solve corresponding undetermined limit. These methods are simple, convenient and easy for students to maser. Besides, these methods can stimulate interests of study, develop innovative thinking and foster science inquiry spirit of students to further lay a solid mathematical foundation for future study.

Keywords

Infinity, theorem, equivalent substitution, limit