**Learning objectives**

- Use differentials to make linear approximations
- Use the gradient to compute directional derivatives
- Understand the geometry of the gradient

**Before class**

- Read Hughes-Hallett sections 14.3, 14.4, 14.5.
- Ponder Hughes-Hallett problems: 14.3: 1, 17, 18, 20, 24, 26; 14.4: 1, 7, 17, 23, 30-35, 48, 64, 65, 66, 74; 4.5: 9, 15, 33, 49, 54.
- Post to Piazza

**In class**

- Work problems
- Examine the Investment-Savings (IS) model in macroeconomics if time allows