I have a question regarding two electric lines running parallel to each other with their current running in opposite direction. Under this set up the electric field points up vertically on the page and the magnetic field points out from the page. I am to show that Maxwell's equations reduce to -dH/dz = epsilon dE/dt and dE/dz = - mu dH/dt. One question I have is dt regards time but what does dz regard. I am guessing that it is the change in displacement that runs along the electric lines, the direction of the current. Is this the correct direction? I have expressions for Maxwell's equations that involve integrals. Are these the ones I should start off with? The reason I ask is I found expressions for Maxwell's equations online that are described by differentials. These seem like easier ground to pick up the problem from. In fact I don't see how I can solve the problem from the integral Maxwell equations. Clearly there must be a way but I don't see it. This website: http://en.wikipedia.org/wiki/Maxwell's_equations has Maxwell's equations in integral and differential form. If I start from differential form then it looks like the equation involving the curl of E does not need to change. The equation involving the curl of H however has an extra term in it which I'm guessing I need to prove is zero under the described problem statement. That equation is: curl of H = J + dD/dt or curl of B = J + dE/dt expressed in the terms I have used. So I guess I need to prove that the curl of H can be expressed as -dH/dz only and that the J term is equal to zero. I'm not real sure where to get started with this problem.