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Nicolae Coculescu
2004 Nicolae Coculescu
2
Nice primitivability result
Nice primitivability result
Source:
December 14, 2019
function
primitives
real analysis
Problem Statement
Consider a function
f
:
R
⟶
R
f:\mathbb{R}\longrightarrow\mathbb{R}
f
:
R
⟶
R
that admits bounded primitives. Prove that the function
g
:
R
⟶
R
g:\mathbb{R}\longrightarrow\mathbb{R}
g
:
R
⟶
R
defined as
f
(
x
)
=
{
x
,
e
m
s
p
;
x
≤
0
f
(
1
/
x
)
⋅
ln
x
,
e
m
s
p
;
x
>
0
f(x)=\left\{ \begin{matrix} x, &   x\le 0 \\ f(1/x)\cdot\ln x ,&   x>0 \end{matrix}\right.
f
(
x
)
=
{
x
,
f
(
1/
x
)
⋅
ln
x
,
e
m
s
p
;
x
≤
0
e
m
s
p
;
x
>
0
admits primitives. Florian Dumitrel
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