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Problems
Contests
International Contests
IMO Longlists
1970 IMO Longlists
19
19
Part of
1970 IMO Longlists
Problems
(1)
Strange Inequality
Source: ILL 1970 - Problem 19.
5/24/2011
Let
1
<
n
∈
N
1<n\in\mathbb{N}
1
<
n
∈
N
and
1
≤
a
∈
R
1\le a\in\mathbb{R}
1
≤
a
∈
R
and there are
n
n
n
number of
x
i
,
i
∈
N
,
1
≤
i
≤
n
x_i, i\in\mathbb{N}, 1\le i\le n
x
i
,
i
∈
N
,
1
≤
i
≤
n
such that
x
1
=
1
x_1=1
x
1
=
1
and
x
i
x
i
−
1
=
a
+
α
i
\frac{x_{i}}{x_{i-1}}=a+\alpha _ i
x
i
−
1
x
i
=
a
+
α
i
for
2
≤
i
≤
n
2\le i\le n
2
≤
i
≤
n
, where
α
i
≤
1
i
(
i
+
1
)
\alpha _i\le \frac{1}{i(i+1)}
α
i
≤
i
(
i
+
1
)
1
. Prove that
x
n
n
−
1
<
a
+
1
n
−
1
\sqrt[n-1]{x_n}< a+\frac{1}{n-1}
n
−
1
x
n
<
a
+
n
−
1
1
.
inequalities
inequalities unsolved