MathDB
Problems
Contests
National and Regional Contests
Russia Contests
Saint Petersburg Mathematical Olympiad
2013 Saint Petersburg Mathematical Olympiad
2
St.Peterburg, P2 Grade 9, 2013
St.Peterburg, P2 Grade 9, 2013
Source:
April 27, 2014
inequalities proposed
inequalities
Problem Statement
if
a
2
+
b
2
+
c
2
+
d
2
=
1
a^2+b^2+c^2+d^2=1
a
2
+
b
2
+
c
2
+
d
2
=
1
prove that
(
1
−
a
)
(
1
−
b
)
≥
c
d
.
(1-a)(1-b)\ge cd.
(
1
−
a
)
(
1
−
b
)
≥
c
d
.
A. Khrabrov
Back to Problems
View on AoPS