1. The problem statement, all variables and given/known data In some cases mj1 and mj2 may be specified at the same time as j because although [j2,j1z] is non-zero, the effect of [j2,j1z] on the state with mj1=j1, mj2=j2 is zero. Confirm that [j2,j1z]| j1j1; j2j2=0 and [j2,j1z] | j1,- j1; j2,- j2=0. 2. Relevant equations what is the procedure to solve this problem 3. The attempt at a solution I evaluated the coummutator of [j2, j1z] = 2ih (L1y L2x- L1x L2y), how to plug in m1, m2.. mj= + or - J. Thank you.