Lipschitz functions are $o(|x|)$?
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Consider a Lipschitz function from $mathbb{R}tomathbb{R}$. Can we say that $lim_{xtoinfty}frac{f(x)}{|x|}=0$. Can we also say that $f$ is differentiable. Continuity is quite evident. But linear order is hard to come by. Any hints? Thanks beforehand.
ordinary-differential-equations continuity lipschitz-functions
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Consider a Lipschitz function from $mathbb{R}tomathbb{R}$. Can we say that $lim_{xtoinfty}frac{f(x)}{|x|}=0$. Can we also say that $f$ is differentiable. Continuity is quite evident. But linear order is hard to come by. Any hints? Thanks beforehand.
ordinary-differential-equations continuity lipschitz-functions
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1
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@user539887 thanks. edited the post
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– vidyarthi
Dec 10 '18 at 7:30
add a comment |
$begingroup$
Consider a Lipschitz function from $mathbb{R}tomathbb{R}$. Can we say that $lim_{xtoinfty}frac{f(x)}{|x|}=0$. Can we also say that $f$ is differentiable. Continuity is quite evident. But linear order is hard to come by. Any hints? Thanks beforehand.
ordinary-differential-equations continuity lipschitz-functions
$endgroup$
Consider a Lipschitz function from $mathbb{R}tomathbb{R}$. Can we say that $lim_{xtoinfty}frac{f(x)}{|x|}=0$. Can we also say that $f$ is differentiable. Continuity is quite evident. But linear order is hard to come by. Any hints? Thanks beforehand.
ordinary-differential-equations continuity lipschitz-functions
ordinary-differential-equations continuity lipschitz-functions
edited Dec 10 '18 at 7:30
vidyarthi
asked Dec 10 '18 at 7:20
vidyarthividyarthi
2,9541832
2,9541832
1
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@user539887 thanks. edited the post
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– vidyarthi
Dec 10 '18 at 7:30
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1
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@user539887 thanks. edited the post
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– vidyarthi
Dec 10 '18 at 7:30
1
1
$begingroup$
@user539887 thanks. edited the post
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– vidyarthi
Dec 10 '18 at 7:30
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@user539887 thanks. edited the post
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– vidyarthi
Dec 10 '18 at 7:30
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2 Answers
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$f(x)=x$ is a counterexample for the first part. Lipschitz functions need not be differentiable at every point but they are differentiable almost everywhere.
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No, consider the function $f(x)=|x|$ which is Lipschitz in $mathbb{R}$ (with constant $1$), not differentiable at $0$, and
$$lim_{xtopminfty}frac{f(x)}{|x|}=pm 1.$$
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@vidyarthi Are you still interested in this question?
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– Robert Z
Jan 16 at 17:34
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2 Answers
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2 Answers
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$f(x)=x$ is a counterexample for the first part. Lipschitz functions need not be differentiable at every point but they are differentiable almost everywhere.
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add a comment |
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$f(x)=x$ is a counterexample for the first part. Lipschitz functions need not be differentiable at every point but they are differentiable almost everywhere.
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add a comment |
$begingroup$
$f(x)=x$ is a counterexample for the first part. Lipschitz functions need not be differentiable at every point but they are differentiable almost everywhere.
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$f(x)=x$ is a counterexample for the first part. Lipschitz functions need not be differentiable at every point but they are differentiable almost everywhere.
answered Dec 10 '18 at 7:23
Kavi Rama MurthyKavi Rama Murthy
58.2k42161
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No, consider the function $f(x)=|x|$ which is Lipschitz in $mathbb{R}$ (with constant $1$), not differentiable at $0$, and
$$lim_{xtopminfty}frac{f(x)}{|x|}=pm 1.$$
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@vidyarthi Are you still interested in this question?
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– Robert Z
Jan 16 at 17:34
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No, consider the function $f(x)=|x|$ which is Lipschitz in $mathbb{R}$ (with constant $1$), not differentiable at $0$, and
$$lim_{xtopminfty}frac{f(x)}{|x|}=pm 1.$$
$endgroup$
$begingroup$
@vidyarthi Are you still interested in this question?
$endgroup$
– Robert Z
Jan 16 at 17:34
add a comment |
$begingroup$
No, consider the function $f(x)=|x|$ which is Lipschitz in $mathbb{R}$ (with constant $1$), not differentiable at $0$, and
$$lim_{xtopminfty}frac{f(x)}{|x|}=pm 1.$$
$endgroup$
No, consider the function $f(x)=|x|$ which is Lipschitz in $mathbb{R}$ (with constant $1$), not differentiable at $0$, and
$$lim_{xtopminfty}frac{f(x)}{|x|}=pm 1.$$
edited Dec 10 '18 at 8:06
answered Dec 10 '18 at 7:22
Robert ZRobert Z
96.3k1065136
96.3k1065136
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@vidyarthi Are you still interested in this question?
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– Robert Z
Jan 16 at 17:34
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@vidyarthi Are you still interested in this question?
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– Robert Z
Jan 16 at 17:34
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@vidyarthi Are you still interested in this question?
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– Robert Z
Jan 16 at 17:34
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@vidyarthi Are you still interested in this question?
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– Robert Z
Jan 16 at 17:34
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@user539887 thanks. edited the post
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– vidyarthi
Dec 10 '18 at 7:30