**Learning objectives**

- Define the curl of a vector field
- Interpret curl as a circulation density
- Gain intuitive understanding of Stokes’ theorem

**Before class**

- Read Hughes-Hallett sections 20.3, 20.4 and 20.5.
- Ponder Hughes-Hallett problems: 20.3: 1, 2, 3, 14, 17; 20.4: 1, 17.
- Complete HW13 on WeBWork
- Post to Piazza
- Write solutions to problems 20.1: 6,16, 37, 38; 20.2: 10 to turn in at the beginning of class.

**In class**

- Problems on curl of a vector field and Stokes’ theorem