Mainly probability theory, mathematical statistics, time series, random process, random integration, generally speaking, random analysis, of course, the middle will use basic calculus, as long as it involves the numerical characteristics of probability, it is inseparable from integration, and the main integration skill is a single partial integral. In fact, actuarial research is a series of expectations for future uncertainty. These expectations are not deterministic, but randomly distributed. So generally speaking, the mathematics used in actuarial science is biased towards statistical mathematics, and stochastic analysis is only aimed at quasi-actuarial test. Graduate students are studying the application of probability, and tutors are doing the application of stochastic process in actuarial science. It is actually a mathematical stochastic optimal control theory, which is based on the theory of stochastic process measurement, functional analysis and stochastic analysis. Therefore, I object that all non-mathematics majors can make actuarial suggestions after taking those courses in mathematics. The simplest, excuse me, what is HJB equation? .