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Lebl-Basic-Analysis-I
· Problem 2.4.8
Sequences and Series
Mathematics · cauchy-sequences
Problem
True or false, prove or find a counterexample: If
{
x
n
}
n
=
1
∞
\{x_n\}_{n=1}^\infty
{
x
n
}
n
=
1
∞
is a Cauchy sequence, then there exists an
M
M
M
such that for all
n
≥
M
n \geq M
n
≥
M
, we have
∣
x
n
+
1
−
x
n
∣
≤
∣
x
n
−
x
n
−
1
∣
|x_{n+1} - x_n| \leq |x_n - x_{n-1}|
∣
x
n
+
1
−
x
n
∣
≤
∣
x
n
−
x
n
−
1
∣
.
Related theory
Sequences Convergence Cauchy Sequences Subsequences
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