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PEN K Problems
5
K 5
K 5
Source:
May 25, 2007
function
arithmetic sequence
Functional Equations
pen
Problem Statement
Find all functions
f
:
N
→
N
f: \mathbb{N}\to \mathbb{N}
f
:
N
→
N
such that for all
n
∈
N
n\in \mathbb{N}
n
∈
N
:
f
(
f
(
m
)
+
f
(
n
)
)
=
m
+
n
.
f(f(m)+f(n))=m+n.
f
(
f
(
m
)
+
f
(
n
))
=
m
+
n
.
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