**Learning objectives**

- Compute partial derivatives algebraically
- Find the equation of a tangent plane:
- where , and

- Use algebraic differentiation to answer questions in applied contexts

**Before class**

- Read Hughes-Hallett 3.5, 9.4.
- Ponder problems 3.5. 7-10, 15, 22, 27, 28; 11, 13, 14, 18, 28, 34.
- Practice symbolic differentiation in 1 variable
- Review the formula sheet
- Review the reasons for the derivative rules

**In class**