Suppose a 2 X 2 matrix X (not necessarily Hermitian 0r unitary) is written as X = a0 + cr - a, where (10 and c1123 are numbers. (a) How are do and ak(k = 1,2,3) related to tr(X) and tr(JkX)? (b) Obtain a0 and can; in terms of the matrix elements X g j