MathDB
Problems
Contests
National and Regional Contests
Romania Contests
District Olympiad
2010 District Olympiad
2
Romania District Olympiad 2010
Romania District Olympiad 2010
Source: Grade X
March 13, 2010
inequalities proposed
inequalities
Problem Statement
Consider two real numbers
a
∈
[
−
2
,
∞
)
,
r
∈
[
0
,
∞
)
a\in [ - 2,\infty)\ ,\ r\in [0,\infty)
a
∈
[
−
2
,
∞
)
,
r
∈
[
0
,
∞
)
and the natural number
n
≥
1
n\ge 1
n
≥
1
. Show that:
r
2
n
+
a
r
n
+
1
≥
(
1
−
r
)
2
n
r^{2n} + ar^n + 1\ge (1 - r)^{2n}
r
2
n
+
a
r
n
+
1
≥
(
1
−
r
)
2
n
Back to Problems
View on AoPS