differentiating electromagnetic field

[jlmac2001]

For question 3, i don't know ho to differentiate the electromagnetic field. Can someone help me?

[jlmac2001]

It's question 2

[HallsofIvy]

If F(x,y,z,t) the "total derivative of F is:
\frac{\partial F}{\partial x}dx+\frac{\partial F}{\partial y}dy+\frac{\partial F}{\partial z}dz+\frac{\partial F}{\partial t}dt

[jlmac2001]

I put the wrong question number down. It's #2 that I need help with. Can someone help?

[HallsofIvy]

Odd. Your second post telling us that it is "problem 2 not problem 3" appears after my post but with an earlier "time stamp".

In any case, I have already given the general formula for "total differential". You might also want to know that, for a vector valued function E, \frac{\partial(E.E)}{\partial x}= 2E.\frac{\partial E}{\partial x}. That should be all you need.