- #1

broegger

- 257

- 0

**Two quick ones :)**

Hi, two questions:

1) How can I find the expectation value of the x-component of the angular momentum, [tex]\langle L_x \rangle[/tex], when I know [tex]\langle L^2 \rangle[/tex] and [tex]\langle L_z \rangle[/tex]?

2) Say, I have a state [tex]|\Psi \rangle[/tex] and two operators A and B represented as matrices. Now, [tex]|\Psi \rangle[/tex] is given as a linear combination of the eigenstates of A and I want to express them as a linear combination of the eigenstates of the operator B instead. How do I do that?

Thanks :)