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Contests
National and Regional Contests
PEN Problems
PEN K Problems
15
15
Part of
PEN K Problems
Problems
(1)
K 15
Source:
5/25/2007
Find all functions
f
:
Z
→
Z
f: \mathbb{Z}\to \mathbb{Z}
f
:
Z
→
Z
such that for all
m
,
n
∈
Z
m,n\in \mathbb{Z}
m
,
n
∈
Z
:
f
(
m
+
f
(
n
)
)
=
f
(
m
)
−
n
.
f(m+f(n))=f(m)-n.
f
(
m
+
f
(
n
))
=
f
(
m
)
−
n
.
function
Functional Equations