(1 pt) A vector field F defined on all of R³ (or all of R²) is conservative if and only if curlF = 0. Determine whether the vector field F = 4 cos yi + 4 sin xj + 3 tan zk is conservative or not by computing its curl. If it is, find its potential function (i.e., find all real-valued functions V such that F = -grad(V)). Use C for the constant of integration. If F is not conservative, enter 'NA' for the potential function. VXF (NA NA NA ). V = NA