A) consider two observables represented by operators a and b. show that it is possible b if and only if a commutes with b to choose a complete set of eigenfunctions which are sharp in both a and for simplicity, you may assume that the eigenvalues of a are non-degenerate. [4] (b) how operators compatible with the hamiltonian can be used to resolve the degeneracy consider an example of a highly degenerate set of energy eigenfunctions. explain