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All-Russian Olympiad Regional Round
2000 All-Russian Olympiad Regional Round
10.5
10.5
Part of
2000 All-Russian Olympiad Regional Round
Problems
(1)
|f(x + y) + sinx + siny| < 2 - All-Russian MO 2000 Regional (R4) 10.5
Source:
9/26/2024
Is there a function
f
(
x
)
f(x)
f
(
x
)
defined for all
x
∈
R
x \in R
x
∈
R
and for all
x
,
y
∈
R
x, y \in R
x
,
y
∈
R
satisfying the inequality
∣
f
(
x
+
y
)
+
sin
x
+
sin
y
∣
<
2
?
|f(x + y) + \sin x + \sin y| < 2?
∣
f
(
x
+
y
)
+
sin
x
+
sin
y
∣
<
2
?
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