1. The problem statement, all variables and given/known data Need to linearize the poisson-boltzmann equation to be used later in the problem. I simply have never linearized an equation and searching google didn't really help me understand. 2. Relevant equations http://img215.imageshack.us/img215/2149/eqnq.jpg [Broken] 3. The attempt at a solution Just need an idea of how to go about this in order to complete the question.