Is There a Mistake in Determining Conservative Fields?

[unscientific]

Homework Statement

Homework Equations

The Attempt at a Solution

I used ∇ X F for part (a) and part (b) and found both to be ≠ 0. Thus both cases F is not conservative.

I have no clue about the second part, as both arent conservative...

 

[Simon Bridge]

Well either there is nothing to be done for the second part or you made a mistake in the first part.