Consider a system with just two linearly independent states (|1) and |2) and the Hamiltonian matrix given by:
H = [41) /2]
Solve the time-independent Schrodinger equation H|ψ⟩ = E|ψ⟩ by showing that the eigenvalues are E1 = 4 and E2 = 1 (using the characteristic equation) and the normalized eigenvectors of H are:
|ψ+⟩ = [1/√2 1/√2]
and
|ψ-⟩ = [-1/√2 1/√2]