Lin's advanced mathematics is very difficult. The textbook "Advanced Mathematics (Economic Management)" edited by Professor Lin and Professor Guo, on the basis of maintaining the traditional teaching system of advanced mathematics in economics and management, appropriately reduces the theoretical difficulty, emphasizes the practical application of calculus in economic management, and at the same time pays attention to expanding knowledge and cultivating students' ability to solve practical problems. Advanced mathematics itself is difficult, but it is not difficult to learn. It is required to master the theorems in books, such as Rolle theorem, mean value theorem, extreme value theorem, etc. All these require accurate memory and application, which requires memorizing all these formulas.