1. Find the limit infimum and the limit supremum of each of the following sequences.

(a) xn=3-(-1)n.

(b) Xn = cos (mrj2).

(c) Xn = (_l)n+l + (-l)njn.

(d) xn=J1+n2j(2n-5).

(e) Xn = Ynjn, where {Yn} is any bounded sequence.

(f) Xn = n(l + (-l)n) + n-1 (( -l)n - 1).

(g) Xn = (n3 + n2 - n + 1)j(n2 + 2n + 5).