1. The problem statement, all variables and given/known data I am a bit confused with how to deal with Kronecker Delta. I need to show that P,i = ( P*δij ),j The i and j are subscripts. 2. Relevant equations 3. The attempt at a solution P,i = ( P*δij ),j = P,j*δij + P*δij,j I assumed I could get rid of P*δij,j leaving me with P,j*δij. After this I am stuck. I'm not sure if I am supposed to consider Kronecker Delta as the Identity Matrix now or not. If I do, I end up with P,j which technically would equal P,i.