Chapter 39, Problem 70GP

(a)

To determine

The information obtained for $\varphi$ when $\Delta L_z=0$.

(b)

To determine

The position of $L_x$ and $L_y$ if $\Delta L_z=0$.

(c)

To determine

That although $L_x$ and $L_y$ are not quantized, nonetheless ${\left(L_x+L_y\right)}^{\frac{1}{2}}={\left[l\left(l+1\right)-m_l^2\right]}^{\frac{1}{2}}\hslash$ is.