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JOM 2015 Shortlist
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G4
Part of
JOM 2015 Shortlist
Problems
(1)
Inequality with concurrent cevians
Source: Junior Olympiad of Malaysia Shortlist 2015 G4
7/17/2015
Let
A
B
C
ABC
A
BC
be a triangle and let
A
D
,
B
E
,
C
F
AD, BE, CF
A
D
,
BE
,
CF
be cevians of the triangle which are concurrent at
G
G
G
. Prove that if
C
F
⋅
B
E
≥
A
F
⋅
E
C
+
A
E
⋅
B
F
+
B
C
⋅
F
E
CF \cdot BE \ge AF \cdot EC + AE \cdot BF + BC \cdot FE
CF
⋅
BE
≥
A
F
⋅
EC
+
A
E
⋅
BF
+
BC
⋅
FE
then
A
G
≤
G
D
AG \le GD
A
G
≤
G
D
.
inequalities