For the state |+), calculate the expectation values and uncertainties for measurements of $S_x$, $S_y$, and $S_z$ in order to verify
hint:
$\langle S_z \rangle = \frac{\hbar}{2}$ $\Delta S_z = 0$
using matrix
$\langle S_x \rangle = 0$ $\Delta S_x \neq 0$
notation is easier
$\langle S_y \rangle = 0$ $\Delta S_y \neq 0$
remember, |+z> state
is $\begin{pmatrix} 1 \\ 0 \end{pmatrix}$
bra is complex conjugate transpose
