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**1. Homework Statement**

Derive equation (1) from equation (2):

(1) [tex]\nabla \cdot D = \rho_f[/tex]

(2) [tex]\nabla \times H = J + \frac{\partial D}{\partial t}[/tex]

**2. Homework Equations**

[PLAIN]http://img198.imageshack.us/img198/4645/maxwell.png [Broken]

**3. The Attempt at a Solution**

[tex]\nabla \times H = J + \frac{\partial D}{\partial t}[/tex]

[tex]\nabla \cdot (\nabla \times H) = \nabla \cdot (J + \frac{\partial D}{\partial t})[/tex]

[tex]0 = \nabla \cdot J \frac{\partial \rho_f}{\partial t}[/tex] (This is assuming no source or sink.)

[tex]-\nabla \cdot J = \frac{\partial \rho_f}{\partial t}[/tex]

Now I'm stuck at the continuity equation. How do I prove that [tex]\int-\nabla \cdot J = \nabla \cdot D[/tex]? (What I want to do is take the integral of both sides.)

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