Let (xn) be a sequence with positive terms. (a) Prove
the following: lim inf xn+1/ xn ≤ lim inf
n√ xn ≤ lim sup n√xn ≤
lim sup xn+1/ xn .
(b) Give example of (xn) where all above inequalities
are strict. Hint; you may consider the following sequence
xn = 2n if n even and xn = 1 if n
odd.
Prove that every sequence in a discrete metric space converges
and is a Cauchy sequence.
This is all that was given to me... so I am unsure how I am
supposed to prove it....
(a) a sequence {an} that is not monotone (nor
eventually monotone) but diverges to ∞
(b) a divergent sequence {an} such that
{an/33} converges
(c) two divergent sequences {an} and {bn}
such that {an + bn} converges to 17
(d) two convergent sequences {an} and {bn}
such that {an/bn} diverges
(e) a sequence with no convergent subsequence
(f) a Cauchy sequence with an unbounded subsequence