Assume C is a circle centered at the origin, oriented counterclockwise, that encloses disk R in the plane. Complete the following steps for the vector field F = (9y, - 2x). a. Calculate the two-dimensional curl of F. b. Calculate the two-dimensional divergence of F. c. Is F irrotational on R? d. Is F source free on R? a. The two-dimensional curl of F is b. The two-dimensional divergence of F is . F irrotational on R because its is zero throughout R. d. F source free on R because its is zero throughout R.