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Lebl-Basic-Analysis-I
· Problem 3.2.18
Continuous Functions
Mathematics · continuous-functions
Problem
Suppose
f
:
[
−
1
,
1
]
→
R
f : [-1, 1] \to \mathbb{R}
f
:
[
−
1
,
1
]
→
R
is a function continuous at all
x
∈
[
−
1
,
1
]
∖
{
0
}
x \in [-1, 1] \setminus \{0\}
x
∈
[
−
1
,
1
]
∖
{
0
}
. Show that for every
ϵ
\epsilon
ϵ
such that
0
<
ϵ
<
1
0 < \epsilon < 1
0
<
ϵ
<
1
, there exists a function
g
:
[
−
1
,
1
]
→
R
g : [-1, 1] \to \mathbb{R}
g
:
[
−
1
,
1
]
→
R
continuous on all of
[
−
1
,
1
]
[-1, 1]
[
−
1
,
1
]
, such that
f
(
x
)
=
g
(
x
)
f(x) = g(x)
f
(
x
)
=
g
(
x
)
for all
x
∈
[
−
1
,
−
ϵ
]
∪
[
ϵ
,
1
]
x \in [-1, -\epsilon] \cup [\epsilon, 1]
x
∈
[
−
1
,
−
ϵ
]
∪
[
ϵ
,
1
]
, and
∣
g
(
x
)
∣
≤
∣
f
(
x
)
∣
|g(x)| \leq |f(x)|
∣
g
(
x
)
∣
≤
∣
f
(
x
)
∣
for all
x
∈
[
−
1
,
1
]
x \in [-1, 1]
x
∈
[
−
1
,
1
]
.
Related theory
Characteristic Functions And Moment Generating Functions
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