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Lebl-Basic-Analysis-I
· Problem 2.5.12
Sequences and Series
Mathematics · cauchy-sequences-series
Problem
Let
x
n
:
=
∑
i
=
1
n
1
/
i
x_n := \sum_{i=1}^{n} 1/i
x
n
:=
∑
i
=
1
n
1/
i
. Show that for every
k
k
k
, we get
lim
n
→
∞
∣
x
n
+
k
−
x
n
∣
=
0
\lim_{n\to\infty} |x_{n+k} - x_n| = 0
lim
n
→
∞
∣
x
n
+
k
−
x
n
∣
=
0
, yet
{
x
n
}
n
=
1
∞
\{x_n\}_{n=1}^{\infty}
{
x
n
}
n
=
1
∞
is not Cauchy.
Related theory
Sequences Convergence Cauchy Sequences Subsequences
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