(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Show [tex]\left[x,f(p)[/tex][tex]\right)][/tex] = [tex]i\hbar\frac{d}{dp}(f(p))\right.[/tex]

2. Relevant equations

I can use [tex]\left[x,p^{n}[/tex][tex]\right)][/tex] = [tex]i\hbar\\n\right.[/tex][tex]p^{n}\right.[/tex]

f(p) = [tex]\Sigma[/tex] [tex]f_{n}[/tex][tex]p^{n}[/tex] (power series expansion)

3. The attempt at a solution

I started by expanding f(p) to the power series which makes

[tex]\left[x,\Sigma\\f_{n}\\p^{n}[/tex][tex]\right)][/tex]

and I know I must use the commutator identity [A, BC] = [A,B]C + B[A,C]

but the power series cannot be split up into two products(BC) ? So I'm not sure how to go on

**Physics Forums - The Fusion of Science and Community**

# Commutator proof

Know someone interested in this topic? Share a link to this question via email,
Google+,
Twitter, or
Facebook

- Similar discussions for: Commutator proof

Loading...

**Physics Forums - The Fusion of Science and Community**