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National and Regional Contests
PEN Problems
PEN K Problems
13
13
Part of
PEN K Problems
Problems
(1)
K 13
Source:
5/25/2007
Find all functions
f
:
Z
→
Z
f: \mathbb{Z}\to \mathbb{Z}
f
:
Z
→
Z
such that for all
m
∈
Z
m\in \mathbb{Z}
m
∈
Z
:
f
(
f
(
m
)
)
=
m
+
1.
f(f(m))=m+1.
f
(
f
(
m
))
=
m
+
1.
function
Functional Equations