1. The problem statement, all variables and given/known data X(x)=(Ae^kx+Be^-kx) Y(y)=(Csin(ky)+D(cos(ky)) V(x,y)=(Ae^kx+Be^-kx)(Csin(ky)+D(cos(ky)) 2. Relevant equations separation of variables 3. The attempt at a solution so our boundary condition says that as x->infinity , V=0 this is only possible if A=0 so A=0 and Be^-kx= 0 so X= Be^-kx and V(x,y)=(e^-kx)(Csin(ky)+D(cos(ky)) why is there an e^-kx on the front. Shouldn't there also be a B?