1. The problem statement, all variables and given/known data Prove that [AnB] =nAn-1[A,B] for integrer n , assume [A,[A,B]]=0=[B,[A,B]] 2. Relevant equations [A,B]=AB-BA 3. The attempt at a solution Does anyone know how i should go to manipulate the exponent n ? I have tried to search but found nothing about a commutator like this properties.