  Recently, we have shown how the interpretation of quantum mechanics due to
Lande' can be used to derive from first principles generalized formulas for the
operators and some eigenvectors for spin 1/2 Though we gave the operators for
all the components of the spin, we did not give the eigenvectors of the
operators for the x and y components of the spin. We now give these vectors. In
addition, we present a new and simple method of deriving the operators for the
x and y components of the spin as well as their vectors from those for the z
component. We give a general proof that the operator for the square of the spin
is the unit matrix multiplied by the value of the square of the spin.
