MathDB
Problems
Contests
National and Regional Contests
Turkey Contests
Turkey MO (2nd round)
2006 Turkey MO (2nd round)
1
turkey nmo 2006 q4
turkey nmo 2006 q4
Source:
January 6, 2007
inequalities unsolved
inequalities
Problem Statement
x
1
,
.
.
.
,
x
n
x_{1},...,x_{n}
x
1
,
...
,
x
n
are positive reals such that their sum and their squares' sum are equal to
t
t
t
. Prove that
∑
i
≠
j
x
i
x
j
≥
(
n
−
1
)
2
⋅
t
t
−
1
\sum_{i\neq{j}}\frac{x_{i}}{x_{j}}\ge\frac{(n-1)^{2}\cdot{t}}{t-1}
∑
i
=
j
x
j
x
i
≥
t
−
1
(
n
−
1
)
2
⋅
t
Back to Problems
View on AoPS