I want to write the dielectric profile of the following system, so I can then write its fourier transform as an integral... The plates are semi-infinite. So far I have: Epsilon, for: -infinity < z <= 0 1, for: 0 < z < ? Epsilon, for: ? <= z < +infinity I need to find the expression given by ? to complete the profile but have no idea how given that its not continious. That will do for now. Any help would be much appreciated. Thanks.