1. The problem statement, all variables and given/known data (1) Prove the space [tex]\ell_\infty[/tex] is complete (2)In [tex]\ell_\infty[/tex](R) , let Y be the subspace of all sequences with only finitely many non-0 terms. Prove that Y is not complete. 3. The attempt at a solution (1)I can show that [tex]\ell\infty[/tex] is complete by taking an arbitrary cauchy sequence and showing that xn[tex]\rightarrow[/tex] x (2)Im not sure how to go about this.I figure the best wat to show that its not complete is to try to prove that it is complete?but im not sure where to start?