Calculus, linear algebra, probability theory and mathematical statistics.

Calculus generally emphasizes calculation, light proof and heavy application. For example, many marginal concepts in economics are actually derivatives.

Linear algebra mainly emphasizes basic concepts, such as matrix and determinant.

Probability theory is generally easy to master. High school calculates probability, but high school only touches discrete random variables, and universities are more continuous random variables.

The content of mathematical statistics is not deep, and it is divided into two parts: parameter estimation and hypothesis testing. Common methods of general parameter estimation (moment estimation, maximum likelihood estimation, etc.). ) to master, other parts to understand.

To learn these things well, the key is to lay a good foundation for the later study of mathematical economics, econometrics, operational research and other disciplines.