domain of definition for $u_x + uu_y = 1$











up vote
2
down vote

favorite












How do i find the domain of definition for $u_x + uu_y = 1$
with $u = x/2$ on $y=x$ , $0 leq x leq 1$



I parametrise by letting $y=s$ , $x=s$ , $u=s/2$ , $0 leq s leq 1$ at $t=0$



The characteristic equations are:
$dx/dt = 1$, $dy/dt = u$, $du/dt = 1$



Solving $dx/dt = 1$ gives $x=t +s$



Solving $du/dt = 1$ gives $u=t+ s/2$



Solving $dy/dt = u$ gives $y = (1/2)t^2 + st/2 + s$



This is where I get stuck,



$t=x-s$ so $y = (1/2)(x-s)^2 + (1/2)s(x-s) + s$



and $0 leq s leq 1$ so am i correct in saying that the domain of definition is the region between $y = (1/2)x^2 $ and $y = (1/2)(x-1)^2 + (1/2)(x-1) + 1$










share|cite|improve this question






















  • I did it by means of another procedure and I get the same result. Maybe you want a full answer...
    – Rafa Budría
    Nov 20 at 11:33















up vote
2
down vote

favorite












How do i find the domain of definition for $u_x + uu_y = 1$
with $u = x/2$ on $y=x$ , $0 leq x leq 1$



I parametrise by letting $y=s$ , $x=s$ , $u=s/2$ , $0 leq s leq 1$ at $t=0$



The characteristic equations are:
$dx/dt = 1$, $dy/dt = u$, $du/dt = 1$



Solving $dx/dt = 1$ gives $x=t +s$



Solving $du/dt = 1$ gives $u=t+ s/2$



Solving $dy/dt = u$ gives $y = (1/2)t^2 + st/2 + s$



This is where I get stuck,



$t=x-s$ so $y = (1/2)(x-s)^2 + (1/2)s(x-s) + s$



and $0 leq s leq 1$ so am i correct in saying that the domain of definition is the region between $y = (1/2)x^2 $ and $y = (1/2)(x-1)^2 + (1/2)(x-1) + 1$










share|cite|improve this question






















  • I did it by means of another procedure and I get the same result. Maybe you want a full answer...
    – Rafa Budría
    Nov 20 at 11:33













up vote
2
down vote

favorite









up vote
2
down vote

favorite











How do i find the domain of definition for $u_x + uu_y = 1$
with $u = x/2$ on $y=x$ , $0 leq x leq 1$



I parametrise by letting $y=s$ , $x=s$ , $u=s/2$ , $0 leq s leq 1$ at $t=0$



The characteristic equations are:
$dx/dt = 1$, $dy/dt = u$, $du/dt = 1$



Solving $dx/dt = 1$ gives $x=t +s$



Solving $du/dt = 1$ gives $u=t+ s/2$



Solving $dy/dt = u$ gives $y = (1/2)t^2 + st/2 + s$



This is where I get stuck,



$t=x-s$ so $y = (1/2)(x-s)^2 + (1/2)s(x-s) + s$



and $0 leq s leq 1$ so am i correct in saying that the domain of definition is the region between $y = (1/2)x^2 $ and $y = (1/2)(x-1)^2 + (1/2)(x-1) + 1$










share|cite|improve this question













How do i find the domain of definition for $u_x + uu_y = 1$
with $u = x/2$ on $y=x$ , $0 leq x leq 1$



I parametrise by letting $y=s$ , $x=s$ , $u=s/2$ , $0 leq s leq 1$ at $t=0$



The characteristic equations are:
$dx/dt = 1$, $dy/dt = u$, $du/dt = 1$



Solving $dx/dt = 1$ gives $x=t +s$



Solving $du/dt = 1$ gives $u=t+ s/2$



Solving $dy/dt = u$ gives $y = (1/2)t^2 + st/2 + s$



This is where I get stuck,



$t=x-s$ so $y = (1/2)(x-s)^2 + (1/2)s(x-s) + s$



and $0 leq s leq 1$ so am i correct in saying that the domain of definition is the region between $y = (1/2)x^2 $ and $y = (1/2)(x-1)^2 + (1/2)(x-1) + 1$







pde parametric






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Nov 19 at 22:24









Rakin Islam

446




446












  • I did it by means of another procedure and I get the same result. Maybe you want a full answer...
    – Rafa Budría
    Nov 20 at 11:33


















  • I did it by means of another procedure and I get the same result. Maybe you want a full answer...
    – Rafa Budría
    Nov 20 at 11:33
















I did it by means of another procedure and I get the same result. Maybe you want a full answer...
– Rafa Budría
Nov 20 at 11:33




I did it by means of another procedure and I get the same result. Maybe you want a full answer...
– Rafa Budría
Nov 20 at 11:33















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%2f3005611%2fdomain-of-definition-for-u-x-uu-y-1%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




















































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.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • 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.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3005611%2fdomain-of-definition-for-u-x-uu-y-1%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

Quarter-circle Tiles

build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

Mont Emei