A.2. Sequences 691
A.2.3.Let{an}and{dn}be sequences of real numbers. Show that
lim
n→∞
(an+dn)≥ lim
n→∞
an+ lim
n→∞
dn.
A.2.4.Let{an}be a sequence of real numbers. Suppose{ank}is a subsequence of
{an}.If{ank}→a 0 ask→∞, show that limn→∞an≤a 0 ≤limn→∞an.