Simplifying Quantum Mechanics with Dirac Notation

AI Thread Summary
The discussion focuses on simplifying a quantum mechanics expression using Dirac notation, specifically <E| (QH - HQ) |E>. The initial confusion arises from understanding how the textbook arrives at the simplification to (E-E) <E|Q|E> = 0. Participants clarify that QH simplifies to the right and HQ to the left, leading to the resolution of the problem. The exchange highlights the importance of manipulating operators correctly in quantum mechanics. Ultimately, the simplification process is successfully understood.
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Homework Statement



trying to simplify (using dirac notation) QM:

<E| (QH - HQ) |E>

using H|E> = E|E>



Homework Equations





The Attempt at a Solution



the textbook says that it simplifies to (E-E) <E|Q|E> = 0 but i can't see how :S
 
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hi bon! :smile:
bon said:
<E| (QH - HQ) |E>

do the QH and the HQ separately …

the QH simplifies to the right, and the HQ simplifies to the left :wink:
 
sorry got it now thanks
 

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