1. The problem statement, all variables and given/known data Hi,I have got a question as follow: Compute the commutation relations of the position operator R and the angular momentum L.Deduce the commutation relations of R^2 with the angular momentum L 2. Relevant equations 3. The attempt at a solution In fact I have got the solutions to this problem.I am having trouble for the 2nd part of the question. In the red box of the image,why did the terms cancel out?Since position vector is commutative I expect they should add up? Thanks!