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Lebl-Basic-Analysis-I
· Problem 2.2.9
Sequences and Series
Mathematics · facts-about-limits-of-sequences
Problem
Suppose
{
x
n
}
n
=
1
∞
\{x_n\}_{n=1}^\infty
{
x
n
}
n
=
1
∞
is a sequence,
x
∈
R
x \in \mathbb{R}
x
∈
R
, and
x
n
≠
x
x_n \neq x
x
n
=
x
for all
n
∈
N
n \in \mathbb{N}
n
∈
N
. Suppose the limit
L
:
=
lim
n
→
∞
∣
x
n
+
1
−
x
∣
∣
x
n
−
x
∣
L := \lim_{n\to\infty} \frac{|x_{n+1} - x|}{|x_n - x|}
L
:=
n
→
∞
lim
∣
x
n
−
x
∣
∣
x
n
+
1
−
x
∣
exists and
L
<
1
L < 1
L
<
1
. Show that
{
x
n
}
n
=
1
∞
\{x_n\}_{n=1}^\infty
{
x
n
}
n
=
1
∞
converges to
x
x
x
.
Related theory
Sequences Convergence Cauchy Sequences Subsequences
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