For each of the following vector fields F, decide whether it is conservative or not by computing curl F. Type in a potential function f (that is, Vf = F). Assume the potential function has a value of zero at the origin. If the vector field is not conservative, type N. A F(x, y) = (-14x - 4y)i + (-4x + 12y)j f(x, y) = B. F(x, y) = -7yi - 6rj f(x, y) = C. F(x, y, 2) = -7ri - 6gj + k f(I, y, 2) = D. F(r,y) = (-7siny)i + (-8y - 7x cosy)j f(x, y) = E. F(x, y, 2) = -7x24 - 4y j + 62 k f ( I, y, > ) = Note: Your answers should be either expressions of x, y and z (e.g. "3xy + 2yz"), or the letter "N"