6. Spin states for two particles [ll]I points] \"'3 examine state". of two spin onehalf particles. For this we have a tensor product vector space with basis states given by |+>|+l~ |+}|-}.- |-)l+}-. l-Wl-lI Consider now the entangled state n: = %(l+}l} Hale). \"le want to establish that this is a rotationall}.r invariant state. For this consider some rotation operator R with the propertyr that R|+:J = |n; +}_. where n is seine unit vector. (a) Why should it be that R|) is [up to a phase} equal to |n; }'? (b) In the tensor product the rotation operator is RR- R. Show that {R59 R) W} is in fact equal to PD} up to a phase. This is the statement of rotational invariance