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    Am I doing this correctly? thanks
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    (Original post by importunate)
    Am I doing this correctly? thanks
    I think you lost a minus sign in the first term for your [p, H] commutator. Since the question does state "for any potential V" you'd generally expect the commutator to depend on the form of V.

    You also lost a minus sign in the second term for [p^2, T].

    An easier way to do these questions is to note that [A, A^n] = 0 for any operator A so it's not always necessary to evaluate the commutator explicitly unless the question says to.
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    however i do it, a comes out to be zero... and not in terms of the potential. what do you get it to be?
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    (Original post by importunate)
    however i do it, a comes out to be zero... and not in terms of the potential. what do you get it to be?
    You have to use the product rule. The d/dx acts on V*psi not just psi since V=V(x)
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    Ok using the product rule I get: -i(hbar)dv/dx

    Is that correct?
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    (Original post by importunate)
    Ok using the product rule I get: -i(hbar)dv/dx

    Is that correct?
    That looks right from memory.
 
 
 
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