1. The problem statement, all variables and given/known data Show that intensity of radiation(EM wave) falls off with depth z as I(z)= Ie^(-2niwz/c) where I = initial intensity and ni=complex paert of refractive index 2. Relevant equations I have tried the solving the solution using poynting vector. I have been pondering over the question over the last two days without any success. I think i am making it more complicated than it needs. to be. I would appreciate it if you point me in the right direction .