Physics, Quantum Physics, Quantum Mechanics, Quantum, Mathematics.
operators can act on bras instead of a ket. For example, let’s say we have an operator Q hat acting on |Ψ⟩ and we want to find the bra version of this. We know that the bra must be the hermitian conjugate of this, so we can find it in the following way: Where I used the identity (AB)† = B†A†. And