vector field: changing vector magnitudes to make it conservative











up vote
3
down vote

favorite
1












Consider a vector field $$vec{F}(x,y)=P(x,y)vec{i}+Q(x,y)vec{j}$$ on an open and simply-connected region. Assume $P$ and $Q$ have continuous partial derivatives.
Under which conditions there exists a positive-valued function $mu (x,y)$ such that $$muvec{F}(x,y)=mu(x,y)P(x,y)vec{i}+mu(x,y)Q(x,y)vec{j}$$ is a conservative vector field?



Thanks for the help!










share|cite|improve this question




















  • 1




    Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
    – amd
    Nov 15 at 0:21












  • What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
    – Arthur
    Nov 15 at 0:22












  • First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
    – FreddyM
    Nov 15 at 0:36






  • 2




    To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
    – FreddyM
    Nov 15 at 0:40

















up vote
3
down vote

favorite
1












Consider a vector field $$vec{F}(x,y)=P(x,y)vec{i}+Q(x,y)vec{j}$$ on an open and simply-connected region. Assume $P$ and $Q$ have continuous partial derivatives.
Under which conditions there exists a positive-valued function $mu (x,y)$ such that $$muvec{F}(x,y)=mu(x,y)P(x,y)vec{i}+mu(x,y)Q(x,y)vec{j}$$ is a conservative vector field?



Thanks for the help!










share|cite|improve this question




















  • 1




    Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
    – amd
    Nov 15 at 0:21












  • What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
    – Arthur
    Nov 15 at 0:22












  • First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
    – FreddyM
    Nov 15 at 0:36






  • 2




    To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
    – FreddyM
    Nov 15 at 0:40















up vote
3
down vote

favorite
1









up vote
3
down vote

favorite
1






1





Consider a vector field $$vec{F}(x,y)=P(x,y)vec{i}+Q(x,y)vec{j}$$ on an open and simply-connected region. Assume $P$ and $Q$ have continuous partial derivatives.
Under which conditions there exists a positive-valued function $mu (x,y)$ such that $$muvec{F}(x,y)=mu(x,y)P(x,y)vec{i}+mu(x,y)Q(x,y)vec{j}$$ is a conservative vector field?



Thanks for the help!










share|cite|improve this question















Consider a vector field $$vec{F}(x,y)=P(x,y)vec{i}+Q(x,y)vec{j}$$ on an open and simply-connected region. Assume $P$ and $Q$ have continuous partial derivatives.
Under which conditions there exists a positive-valued function $mu (x,y)$ such that $$muvec{F}(x,y)=mu(x,y)P(x,y)vec{i}+mu(x,y)Q(x,y)vec{j}$$ is a conservative vector field?



Thanks for the help!







multivariable-calculus vector-analysis






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 15 at 0:35

























asked Nov 15 at 0:16









FreddyM

162




162








  • 1




    Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
    – amd
    Nov 15 at 0:21












  • What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
    – Arthur
    Nov 15 at 0:22












  • First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
    – FreddyM
    Nov 15 at 0:36






  • 2




    To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
    – FreddyM
    Nov 15 at 0:40
















  • 1




    Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
    – amd
    Nov 15 at 0:21












  • What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
    – Arthur
    Nov 15 at 0:22












  • First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
    – FreddyM
    Nov 15 at 0:36






  • 2




    To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
    – FreddyM
    Nov 15 at 0:40










1




1




Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
– amd
Nov 15 at 0:21






Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
– amd
Nov 15 at 0:21














What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
– Arthur
Nov 15 at 0:22






What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
– Arthur
Nov 15 at 0:22














First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
– FreddyM
Nov 15 at 0:36




First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
– FreddyM
Nov 15 at 0:36




2




2




To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
– FreddyM
Nov 15 at 0:40






To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
– FreddyM
Nov 15 at 0:40

















active

oldest

votes











Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

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',
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
});


}
});














 

draft saved


draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2999006%2fvector-field-changing-vector-magnitudes-to-make-it-conservative%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes
















 

draft saved


draft discarded



















































 


draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2999006%2fvector-field-changing-vector-magnitudes-to-make-it-conservative%23new-answer', 'question_page');
}
);

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







Popular posts from this blog

How do I know what Microsoft account the skydrive app is syncing to?

When does type information flow backwards in C++?

Grease: Live!