1. The problem statement, all variables and given/known data psiplus = 1/sqrt(2) (psi(1,2) + psi(2,1)) Is PsiPlus an eigenfunction of the Hamiltonian operator? If so, what are the eigenvalues for the energy corresponding to PsiPlus in units of (h^2/(8ma)^2)? 2. Relevant equations psiplus = 1/sqrt(2) (psi(1,2) + psi(2,1)) psi12 =2/a sin(Pi*x/a) *sin (2Pi*y/a) (2D Particle in Box) psi21 =2/a sin(2*Pi*x/a) *sin (Pi*y/a) 3. The attempt at a solution I don't understand some of the core concepts yet, so I don't know how to approach this problem.