1. The problem statement, all variables and given/known data Hi guys, I've not started a course on QM yet, but we are currently learning the maths used in QM. Show, by taking the trace of both sides show that finite dimensional matrix representations of the momentum operator p and the position operator x which satisfy [p, x] = −ih are not possible. Why does this argument fail if the matrices are infinite-dimensional (as Heisenberg’s were)? 2. Relevant equations 3. The attempt at a solution Are the position and momentum operators supposed to be matrices? I've looked up on wikipedia, the position operator is more of like ih(d/dp) while the momentum operator is ih(d/dx).