9. i) Show that F(x, y, z) = yz₁+xzj+xy k is a conservative vector field, and find a potential function f(x,y,z) such that F = gradf. Ans: xyz+c ii) Evaluate the work done by F acting on an object as it moves along any path from A (1, 0, 1) to B (2, 1, 3). (Hint: Use the fact that [F.dr is independent of path). (Ans: 12) [F.dr C