2. Master the solutions of differential equations, homogeneous differential equations and first-order linear differential equations with separable variables.

3. Second-order homogeneous linear differential equations with constant coefficients can be solved.

4. Knowing the properties and structure theorems of solutions of linear differential equations, you can solve second-order non-homogeneous linear differential equations with constant coefficients with polynomial, exponential function, sine function and cosine function as free terms.

5. Understand the concepts of difference and difference equation and their general and special solutions.

6. Understand the solution method of the first-order linear difference equation with constant coefficients.

7. Can use differential equations to solve simple economic application problems.

Don't look at what you know first, and then look at it.