Dear friends,

can u help me to solve the following problem

Show that Y={x|x=(\lambda_j \in l^2, \lambda_2n=0, n\in N} is closed subspace of l^2 and find annihilator Y*. What is the annihilator Y* if Y=span{\epsilon_1,......\epsilon_n}\subset \subset l^2, where \epsilon_j = (\delta_jk))?