(a) show that the pauli spin matrices (problem 6.6) are hermitian. (b) show that the pauli spin matrices satisfy the jacobi identity ˆ a, [b, c]˜ + ˆ b, [c, a]˜ + ˆ c, [a, b]˜ = 0 where [a, b] is the commutator of a, b [see (6.3)]. (c) generalize (b) to prove the jacobi identity for any (conformable) matrices a, b, c. also see chapter 6, problem 3.14.