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Poland - First Round
1993 Poland - First Round
6
6
Part of
1993 Poland - First Round
Problems
(1)
f^n(x) = 1 implies f(1) = 1
Source: Poland Math Olympiad 1993 Round 1 #6
6/3/2023
The function
f
:
R
⟶
R
f: R \longrightarrow R
f
:
R
⟶
R
is continuous. Prove that if for every real number
x
x
x
, there exists a positive integer
n
n
n
, such that
(
f
∘
f
∘
.
.
.
∘
f
)
⏟
n
(
x
)
=
1
\underbrace{(f \circ f \circ ... \circ f)}_{n}(x) = 1
n
(
f
∘
f
∘
...
∘
f
)
(
x
)
=
1
, then
f
(
1
)
=
1
f(1) = 1
f
(
1
)
=
1
.
function