Problem: Which, if either, of the two force fields F1=-yi+xj+zk, F2=yi+xj+zk is conservative? Calculate for each field the work done in moving a particle counterclockwise around the circle x=cos(t), y=sin(t) in the (x,y) plane. Answer: I got the part in telling if the force fields are conservative. F1 is not conservative because d/dx(Fy)-d/dy(Fx) is 2. F2 is conservative because everything is equal to zero. How do I calculate the work done in each field? I don't get it.