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Soros Olympiad in Mathematics
VI Soros Olympiad 1999 - 2000 (Russia)
8.7
8.7
Part of
VI Soros Olympiad 1999 - 2000 (Russia)
Problems
(1)
1/(x+y)^2+1/x^2+1/y^2>=9/4xy (VI Soros Olympiad 1990-00 R1 8.7)
Source:
5/27/2024
Prove that for any positive real
x
x
x
and
y
y
y
, holds the inequality
1
(
x
+
y
)
2
+
1
x
2
+
1
y
2
≥
9
4
x
y
\frac{1}{(x+y)^2}+\frac{1}{x^2}+\frac{1}{y^2} \ge \frac{9}{4xy}
(
x
+
y
)
2
1
+
x
2
1
+
y
2
1
≥
4
x
y
9
algebra
inequalities