**Learning objectives**

- Work with models using 1st order linear equations
- Solve equations that can be put in the form
- Recognize 1st order linear DEs:
- undriven (aka homogeneous) if , otherwise driven

- Solve 1st order linear DEs
- where
- and are ANY single solutions () of the undriven () and driven () DEs

- Find and
- Uniqueness and existence theorems for 1st order linear DEs

**In class**

- Work problems on separable differential equations
- Work problems on 1st order linear equations