v_pino
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Homework Statement
Find the hermitian conjugates, where A and B are operators.
a.) AB-BA
b.) AB+BA
c.) i(AB+BA)
d.) A^\dagger A
Homework Equations
(AB)^\dagger =B^\dagger A^\dagger
The Attempt at a Solution
Are they correct and can I simplify them more?
a.) (AB-BA)^\dagger = (AB)^\dagger - (BA)^\dagger= B^\dagger A^\dagger - A^\dagger B^\dagger = BA-AB = -(AB-BA)
b.) (AB+BA)^\dagger = (AB)^\dagger + (BA)^\dagger= B^\dagger A^\dagger + A^\dagger B^\dagger = BA+AB
c.) [i(AB+BA)]^\dagger = -i[(AB)^\dagger + (BA)^\dagger]= -i(B^\dagger A^\dagger + A^\dagger B^\dagger) = BA+AB
d.) [A^\dagger A]^\dagger = A^\dagger (A^\dagger)^\dagger=A^\dagger A