# Update on Mathematics and Physics HW set

The Pauli matrix for 3.b) should read like this

$S_z = \frac{\hbar}{2} \begin{pmatrix} 1 & 0 \\ 0 & -1 \end{pmatrix}\,;$
That is, there is a minus sign in the lower right corner of the matrix.
Otherwise, the eigenvalues become trivial for an identity.