# Homework Help: Can someone help me with expectation values for the radial wavefunction?

1. Sep 23, 2010

### cwhitis

Show that the expectation value of Lz is -2h for the radial wavefunction Y2,-2. ??? Can someone do this?

2. Sep 23, 2010

### javiergra24

Use the matrix representation for the basis l=2.

Remember that
$$\mathbf{L_z} = m\hbar$$

Last edited: Sep 24, 2010
3. Sep 23, 2010

### cwhitis

Thanks but I still don't understand, could you work it out?

4. Sep 23, 2010

### vela

Staff Emeritus
That's not how it works here. It's against the forum rules to provide solutions, and you need to show some attempt at solving the problem before you'll get help here.

5. Sep 24, 2010

### javiergra24

The wavefunction is normalized. Radial function cannot be Y, that's the spherical harmonics. Just apply the expected value in the ket-bra notation