Consider the vector field F(x, y, z) = (3+2xe" - z sin(x))i + (xe" - 6yz)j + (2z cos(x) 2y)k. (a) To determine whether F is conservative, and if it is, find its potential function; (b) Find the work done by the force field F on an object that moves from (0, -1, -1) to (, 1, 1).