Due to the contradiction between Eqs. (9.2) and (9.5), we know that there must be an extra term in the ∇×B relation, as we found in Eq. (9.10). Call this term W. In the text, we used the Lorentz transformations to motivate a guess for W. Find W here by taking the divergence of both sides of ∇×B=μ0J+W. Assume that the only facts you are allowed to work with are (1) ∇⋅E=ρ/ϵ0, (2) ∇⋅B=0, (3) ∇⋅J=−∂ρ/∂t, and (4) ∇×B=μ0J in the case of steady currents.