1. The problem statement, all variables and given/known data Let the Hermitian operator A^ corresponding to the observable A have two eigenstates |a1> and |a2> with eigenvalues a1 and a2, respectively, where a1 ≠ a2. Show that A^ can be written in the form A^ = a1|a1><a1| + a2|a2><a2|. 2. Relevant equations 3. The attempt at a solution I reached out the instructor for some guidance but I am still confused. To my understanding i should start with A^|ψ>. Where |ψ> is some arbitrary spin state. and i don't know where to go from there.