- #1
itai
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Homework Statement
given an opeator A, prove that the commutator satisfies:
[A,f(A)]=0
Homework Equations
[A,f(A)]=Af(A)-f(A)A
The Attempt at a Solution
I don't know how to continue from Af(A)-f(A)A=0
I can't just say that f(A)A=Af(A).
Any ideas?