1. The problem statement, all variables and given/known data A square is made up of four plates with a potential of zero on the top and bottom plates at (x,L/2) and (x,-L/2), and a potential of cos(πy/L)+cos(3πy/L). Find the potential and electric fields inside the square. 3. The attempt at a solution I start with V=(Aekx+Be-kx)(Csin(ky)+Dcos(ky)) Then I am supposed to use the boundary conditions stated above to determine values for A,B,C,D, and k. My book has an example of this. However, I can't figure out how to use these conditions to find the values. Could someone point me in the right direction?