# Commutator of [x,p e^(-p) ]

1. Jun 16, 2015

### Prins

• Poster has been warned that he needs to show effort before he can be given help
1. The problem statement, all variables and given/known data
commutator of [x,p e^(-p) ]

2. Relevant equations

3. The attempt at a solution

2. Jun 16, 2015

### blue_leaf77

what is p in the e^(-p)?

3. Jun 16, 2015

### ensign_nemo

If it's the usual notation for quantum mechanics, x is position and p is momentum.

4. Jun 16, 2015

### henil

its just the usual commutation relation of x and p with e^(-p) in multiplication.
the method of solving remains the same.

5. Jun 16, 2015

### blue_leaf77

I will assume that the multiplicative factor which should exist next to the momentum in the exponential in order to conform with the dimensionality is presumed to be unity. There is a shortcut formula for calculating commutators of the form [x,f(p)] and [p,g(x)]. In case you never heard about it, you should then do the calculation by first expanding $e^{-p}$ into power series and use the fundamental commutation relation between x and p.

6. Jun 18, 2015

### Staff: Mentor

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