3.8 a) check that the eigenvalues of the hermitian operator in example 3.1 are real. show that the eigenfunctions are orthogonal. Qf = if' the eigenvalues are 0,+- 1, etc., which are obviously real. pick two arbitrary eigenfunctions: f = A exp(-i q phi) g = A exp(-i q' phi) = A*A int[exp(i q phi) exp(-i q' phi)] dphi[0,2pi] = A*A int[exp(i (q - q') phi)] dphi[0,2pi] = A*A [i(q-q')]^-1 [exp(i(q-q') phi)]|[0,2pi]