3. Let )=e-ito: (|+) |+)). Calculate the reduced density matrix pi(t) = tr₂|)(. (Find pi(t) as a matrix in the basis {|0), [1]}.) Find all values of t≥ 0 for which ) is entangled. Notation: 0, 0, 0, are the Pauli matrices; σ|0) = |0), σ|1) = -|1), |±) = (10) ±|1))