||On problem 3, is the region supposed to be an equilateral triangle?
||The question about potential V should be the last thing in the problem. You should integrate the charge density in the case where the planes are grounded.
||For problem 3 a), is it considered sufficient to
determine the general relationship for the cutoff frequency?
Or is it necessary to write down expressions for the ALL of the field
||For part (a), yes. But note that you are asked for all the field
components in part (c).
||Problem 1. What do you mean when you say to not ignore the effect of the square?
||You should take a/b << 1 but not equal to zero. That is, you must have at least one term in your answer containing a.