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Mathematics
Mathematics
Problem
Let
A
=
{
a
,
b
,
c
,
d
}
A=\{a,b,c,d\}
A
=
{
a
,
b
,
c
,
d
}
and
B
=
{
1
,
2
,
3
}
B=\{1,2,3\}
B
=
{
1
,
2
,
3
}
. A function
f
:
A
→
B
f:A\to B
f
:
A
→
B
is defined by
f
(
a
)
=
1
,
f
(
b
)
=
2
,
f
(
c
)
=
1
,
f
(
d
)
=
3
f(a)=1,\;f(b)=2,\;f(c)=1,\;f(d)=3
f
(
a
)
=
1
,
f
(
b
)
=
2
,
f
(
c
)
=
1
,
f
(
d
)
=
3
. State whether
f
f
f
is injective and give a reason.
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