**Learning objectives**

- Work with a system of differential equations to model the spread of disease
- Investigate linear systems of differential equations

**Before class**

- Read Hughes-Hallett 10.7.
- Ponder problems 10.7.3,4,8,12abc.
- Consult the main points of the lesson

**In class**

- Discuss the SIR model
- Work with systems of DEs