How To solve this type of inequation
$begingroup$
Let $f$ be a regular $2pi-$periodic function .
How to find the functions that solve this inequality $a le f+f^{'}+f^{"} le b$ where $a,b in mathbb{R}_{+}$ .
Could you give me some books to deal with this type of problem?
Thanks
real-analysis inequality periodic-functions
$endgroup$
add a comment |
$begingroup$
Let $f$ be a regular $2pi-$periodic function .
How to find the functions that solve this inequality $a le f+f^{'}+f^{"} le b$ where $a,b in mathbb{R}_{+}$ .
Could you give me some books to deal with this type of problem?
Thanks
real-analysis inequality periodic-functions
$endgroup$
$begingroup$
Since the function is periodic, can't you use a general fourier series and apply your condition to it?
$endgroup$
– Eddy
Jan 1 at 16:32
$begingroup$
thaanks ,yes but what type of information we can concloude about the fourier coefficients from the inequality " fourier series is less than a constant" ?
$endgroup$
– T A R I K
Jan 1 at 16:36
$begingroup$
What's the context, any special reason why you want to find such solutions? Classifying all such functions seems like a hard task. Finding some solutions is much easier. Take for example $f(x) = c + sum c_nsin(2pi nx)$ with $cin(a,b)$ and take $c_n$'s "small enough"
$endgroup$
– Winther
Jan 1 at 16:46
$begingroup$
thank you , i would like to Classifying all such functions
$endgroup$
– T A R I K
Jan 1 at 17:23
add a comment |
$begingroup$
Let $f$ be a regular $2pi-$periodic function .
How to find the functions that solve this inequality $a le f+f^{'}+f^{"} le b$ where $a,b in mathbb{R}_{+}$ .
Could you give me some books to deal with this type of problem?
Thanks
real-analysis inequality periodic-functions
$endgroup$
Let $f$ be a regular $2pi-$periodic function .
How to find the functions that solve this inequality $a le f+f^{'}+f^{"} le b$ where $a,b in mathbb{R}_{+}$ .
Could you give me some books to deal with this type of problem?
Thanks
real-analysis inequality periodic-functions
real-analysis inequality periodic-functions
asked Jan 1 at 16:23
T A R I KT A R I K
297
297
$begingroup$
Since the function is periodic, can't you use a general fourier series and apply your condition to it?
$endgroup$
– Eddy
Jan 1 at 16:32
$begingroup$
thaanks ,yes but what type of information we can concloude about the fourier coefficients from the inequality " fourier series is less than a constant" ?
$endgroup$
– T A R I K
Jan 1 at 16:36
$begingroup$
What's the context, any special reason why you want to find such solutions? Classifying all such functions seems like a hard task. Finding some solutions is much easier. Take for example $f(x) = c + sum c_nsin(2pi nx)$ with $cin(a,b)$ and take $c_n$'s "small enough"
$endgroup$
– Winther
Jan 1 at 16:46
$begingroup$
thank you , i would like to Classifying all such functions
$endgroup$
– T A R I K
Jan 1 at 17:23
add a comment |
$begingroup$
Since the function is periodic, can't you use a general fourier series and apply your condition to it?
$endgroup$
– Eddy
Jan 1 at 16:32
$begingroup$
thaanks ,yes but what type of information we can concloude about the fourier coefficients from the inequality " fourier series is less than a constant" ?
$endgroup$
– T A R I K
Jan 1 at 16:36
$begingroup$
What's the context, any special reason why you want to find such solutions? Classifying all such functions seems like a hard task. Finding some solutions is much easier. Take for example $f(x) = c + sum c_nsin(2pi nx)$ with $cin(a,b)$ and take $c_n$'s "small enough"
$endgroup$
– Winther
Jan 1 at 16:46
$begingroup$
thank you , i would like to Classifying all such functions
$endgroup$
– T A R I K
Jan 1 at 17:23
$begingroup$
Since the function is periodic, can't you use a general fourier series and apply your condition to it?
$endgroup$
– Eddy
Jan 1 at 16:32
$begingroup$
Since the function is periodic, can't you use a general fourier series and apply your condition to it?
$endgroup$
– Eddy
Jan 1 at 16:32
$begingroup$
thaanks ,yes but what type of information we can concloude about the fourier coefficients from the inequality " fourier series is less than a constant" ?
$endgroup$
– T A R I K
Jan 1 at 16:36
$begingroup$
thaanks ,yes but what type of information we can concloude about the fourier coefficients from the inequality " fourier series is less than a constant" ?
$endgroup$
– T A R I K
Jan 1 at 16:36
$begingroup$
What's the context, any special reason why you want to find such solutions? Classifying all such functions seems like a hard task. Finding some solutions is much easier. Take for example $f(x) = c + sum c_nsin(2pi nx)$ with $cin(a,b)$ and take $c_n$'s "small enough"
$endgroup$
– Winther
Jan 1 at 16:46
$begingroup$
What's the context, any special reason why you want to find such solutions? Classifying all such functions seems like a hard task. Finding some solutions is much easier. Take for example $f(x) = c + sum c_nsin(2pi nx)$ with $cin(a,b)$ and take $c_n$'s "small enough"
$endgroup$
– Winther
Jan 1 at 16:46
$begingroup$
thank you , i would like to Classifying all such functions
$endgroup$
– T A R I K
Jan 1 at 17:23
$begingroup$
thank you , i would like to Classifying all such functions
$endgroup$
– T A R I K
Jan 1 at 17:23
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3058619%2fhow-to-solve-this-type-of-inequation%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3058619%2fhow-to-solve-this-type-of-inequation%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
Since the function is periodic, can't you use a general fourier series and apply your condition to it?
$endgroup$
– Eddy
Jan 1 at 16:32
$begingroup$
thaanks ,yes but what type of information we can concloude about the fourier coefficients from the inequality " fourier series is less than a constant" ?
$endgroup$
– T A R I K
Jan 1 at 16:36
$begingroup$
What's the context, any special reason why you want to find such solutions? Classifying all such functions seems like a hard task. Finding some solutions is much easier. Take for example $f(x) = c + sum c_nsin(2pi nx)$ with $cin(a,b)$ and take $c_n$'s "small enough"
$endgroup$
– Winther
Jan 1 at 16:46
$begingroup$
thank you , i would like to Classifying all such functions
$endgroup$
– T A R I K
Jan 1 at 17:23