1. The problem statement, all variables and given/known data We have a sphere with a polarization kr. I need to show that the electric displacement D=0 everywhere. 2. Relevant equations ∫closed surfaceD.dS=qfree 3. The attempt at a solution qfree=0 everywhere so the flux of D is zero everywhere. Clearly D=0 everywhere does solve this, but so could possibly many other things - how do I show D=0 is the solution? This is a very niggly and annoying to think about! Thanks for any help.