QM--- matrix exponentiation 1. The problem statement, all variables and given/known data \ How do you go about exponentiating a 3*3 matrix? for example if you have <θ,∅|exp(-i*∅*Ly/h)|l,m> 2. Relevant equations I know how to exponentiate a two cross two diagonalized matrix. you just exponentiate the diagonal terms. However, in my question, all diagonal entries are zero. So what do I do?