**Learning objectives**

- Interpret partial derivatives as multipliers
- Compute partial derivatives starting from tables, contour diagrams, and formulas

**Before class**

- Review differentiation in 1 and 2 variables.
- Read Section 1 on Derivatives as Multipliers
- Read Hughes-Hallett sections 14.1, 14.2, 14.3.
- Ponder Hughes-Hallett problems:14.1: 1, 3, 5, 9, 10, 11, 23, (34 for a medical application); 14.2: 1, 3, 5, 41; 14.3: 1, 17, 20, 24.

**In class**

- Review: How to think about derivatives and differentiation rules and some justifications
- Introduce partial derivatives and work problems
- Practice with visual representations of 2-variable function: drug concentrations