How to evaluate a parameterized surface integral?












0














Suppose you have to evaluate the surface integral $$intint_S (x^2+y^2+4)space dS$$ where $S$ is the surface parameterized by $textbf{r} = <2uv, u^2-v^2, u^2+v^2>$ with $u^2+v^2 le 16.$



I know the equation to solve the surface integral is $$intint_S f space dS = intint_S f(textbf{r}(u,v))space |textbf{r}_u times textbf{r}_v |space du space dv$$ and I will have no trouble taking the cross product or evaluating the integral. However, how would one go about finding the limits for $S$? I don't even remotely know what $textbf{r} = <2uv, u^2-v^2, u^2+v^2>$ might be. Is there some way maybe to transform $textbf{r}$ to an explicit $z = f(x,y)$?



Thanks.










share|cite|improve this question






















  • The domain in the right handed double integral is not the same of the left handed one. In fact, the domain in the right handed integral is the parametrization's domain.
    – DiegoMath
    Nov 22 at 21:05
















0














Suppose you have to evaluate the surface integral $$intint_S (x^2+y^2+4)space dS$$ where $S$ is the surface parameterized by $textbf{r} = <2uv, u^2-v^2, u^2+v^2>$ with $u^2+v^2 le 16.$



I know the equation to solve the surface integral is $$intint_S f space dS = intint_S f(textbf{r}(u,v))space |textbf{r}_u times textbf{r}_v |space du space dv$$ and I will have no trouble taking the cross product or evaluating the integral. However, how would one go about finding the limits for $S$? I don't even remotely know what $textbf{r} = <2uv, u^2-v^2, u^2+v^2>$ might be. Is there some way maybe to transform $textbf{r}$ to an explicit $z = f(x,y)$?



Thanks.










share|cite|improve this question






















  • The domain in the right handed double integral is not the same of the left handed one. In fact, the domain in the right handed integral is the parametrization's domain.
    – DiegoMath
    Nov 22 at 21:05














0












0








0


1





Suppose you have to evaluate the surface integral $$intint_S (x^2+y^2+4)space dS$$ where $S$ is the surface parameterized by $textbf{r} = <2uv, u^2-v^2, u^2+v^2>$ with $u^2+v^2 le 16.$



I know the equation to solve the surface integral is $$intint_S f space dS = intint_S f(textbf{r}(u,v))space |textbf{r}_u times textbf{r}_v |space du space dv$$ and I will have no trouble taking the cross product or evaluating the integral. However, how would one go about finding the limits for $S$? I don't even remotely know what $textbf{r} = <2uv, u^2-v^2, u^2+v^2>$ might be. Is there some way maybe to transform $textbf{r}$ to an explicit $z = f(x,y)$?



Thanks.










share|cite|improve this question













Suppose you have to evaluate the surface integral $$intint_S (x^2+y^2+4)space dS$$ where $S$ is the surface parameterized by $textbf{r} = <2uv, u^2-v^2, u^2+v^2>$ with $u^2+v^2 le 16.$



I know the equation to solve the surface integral is $$intint_S f space dS = intint_S f(textbf{r}(u,v))space |textbf{r}_u times textbf{r}_v |space du space dv$$ and I will have no trouble taking the cross product or evaluating the integral. However, how would one go about finding the limits for $S$? I don't even remotely know what $textbf{r} = <2uv, u^2-v^2, u^2+v^2>$ might be. Is there some way maybe to transform $textbf{r}$ to an explicit $z = f(x,y)$?



Thanks.







multivariable-calculus surface-integrals parametrization






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Nov 22 at 20:58









Art

3127




3127












  • The domain in the right handed double integral is not the same of the left handed one. In fact, the domain in the right handed integral is the parametrization's domain.
    – DiegoMath
    Nov 22 at 21:05


















  • The domain in the right handed double integral is not the same of the left handed one. In fact, the domain in the right handed integral is the parametrization's domain.
    – DiegoMath
    Nov 22 at 21:05
















The domain in the right handed double integral is not the same of the left handed one. In fact, the domain in the right handed integral is the parametrization's domain.
– DiegoMath
Nov 22 at 21:05




The domain in the right handed double integral is not the same of the left handed one. In fact, the domain in the right handed integral is the parametrization's domain.
– DiegoMath
Nov 22 at 21:05










1 Answer
1






active

oldest

votes


















1














You do not need know how the surface is. Notice that the domain of the parametrizations is a disc of radius 4.



Hint: Since the domain is a disc, try integrate the right hand double integral by using polar coordinates.



I hope I have helped you.






share|cite|improve this answer





















  • So $S$ is not the entire surface?
    – Art
    Nov 22 at 21:07










  • $S$ is given by the parametrization. What do you mean with entire surface?
    – DiegoMath
    Nov 22 at 21:12












  • The limits for S in $intint_S$ are not for the entire surface?
    – Art
    Nov 22 at 21:14








  • 1




    You write this: where $S$ is the surface parameterized by $r=langle 2uv,u^2−v^2,u^2+v^2rangle$ with $u^2+v^2leq16$. So, your entire surface is given by this parametrization
    – DiegoMath
    Nov 22 at 21:16








  • 1




    For example, if your surface $S$ is given by $r=langle u,v,u+vrangle$ where $0leq uleq 1$ and $0leq vleq 1$, then the surface is a piece of a plane and this is the entire surface
    – DiegoMath
    Nov 22 at 21:19











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',
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
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3009653%2fhow-to-evaluate-a-parameterized-surface-integral%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









1














You do not need know how the surface is. Notice that the domain of the parametrizations is a disc of radius 4.



Hint: Since the domain is a disc, try integrate the right hand double integral by using polar coordinates.



I hope I have helped you.






share|cite|improve this answer





















  • So $S$ is not the entire surface?
    – Art
    Nov 22 at 21:07










  • $S$ is given by the parametrization. What do you mean with entire surface?
    – DiegoMath
    Nov 22 at 21:12












  • The limits for S in $intint_S$ are not for the entire surface?
    – Art
    Nov 22 at 21:14








  • 1




    You write this: where $S$ is the surface parameterized by $r=langle 2uv,u^2−v^2,u^2+v^2rangle$ with $u^2+v^2leq16$. So, your entire surface is given by this parametrization
    – DiegoMath
    Nov 22 at 21:16








  • 1




    For example, if your surface $S$ is given by $r=langle u,v,u+vrangle$ where $0leq uleq 1$ and $0leq vleq 1$, then the surface is a piece of a plane and this is the entire surface
    – DiegoMath
    Nov 22 at 21:19
















1














You do not need know how the surface is. Notice that the domain of the parametrizations is a disc of radius 4.



Hint: Since the domain is a disc, try integrate the right hand double integral by using polar coordinates.



I hope I have helped you.






share|cite|improve this answer





















  • So $S$ is not the entire surface?
    – Art
    Nov 22 at 21:07










  • $S$ is given by the parametrization. What do you mean with entire surface?
    – DiegoMath
    Nov 22 at 21:12












  • The limits for S in $intint_S$ are not for the entire surface?
    – Art
    Nov 22 at 21:14








  • 1




    You write this: where $S$ is the surface parameterized by $r=langle 2uv,u^2−v^2,u^2+v^2rangle$ with $u^2+v^2leq16$. So, your entire surface is given by this parametrization
    – DiegoMath
    Nov 22 at 21:16








  • 1




    For example, if your surface $S$ is given by $r=langle u,v,u+vrangle$ where $0leq uleq 1$ and $0leq vleq 1$, then the surface is a piece of a plane and this is the entire surface
    – DiegoMath
    Nov 22 at 21:19














1












1








1






You do not need know how the surface is. Notice that the domain of the parametrizations is a disc of radius 4.



Hint: Since the domain is a disc, try integrate the right hand double integral by using polar coordinates.



I hope I have helped you.






share|cite|improve this answer












You do not need know how the surface is. Notice that the domain of the parametrizations is a disc of radius 4.



Hint: Since the domain is a disc, try integrate the right hand double integral by using polar coordinates.



I hope I have helped you.







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Nov 22 at 21:02









DiegoMath

2,0491021




2,0491021












  • So $S$ is not the entire surface?
    – Art
    Nov 22 at 21:07










  • $S$ is given by the parametrization. What do you mean with entire surface?
    – DiegoMath
    Nov 22 at 21:12












  • The limits for S in $intint_S$ are not for the entire surface?
    – Art
    Nov 22 at 21:14








  • 1




    You write this: where $S$ is the surface parameterized by $r=langle 2uv,u^2−v^2,u^2+v^2rangle$ with $u^2+v^2leq16$. So, your entire surface is given by this parametrization
    – DiegoMath
    Nov 22 at 21:16








  • 1




    For example, if your surface $S$ is given by $r=langle u,v,u+vrangle$ where $0leq uleq 1$ and $0leq vleq 1$, then the surface is a piece of a plane and this is the entire surface
    – DiegoMath
    Nov 22 at 21:19


















  • So $S$ is not the entire surface?
    – Art
    Nov 22 at 21:07










  • $S$ is given by the parametrization. What do you mean with entire surface?
    – DiegoMath
    Nov 22 at 21:12












  • The limits for S in $intint_S$ are not for the entire surface?
    – Art
    Nov 22 at 21:14








  • 1




    You write this: where $S$ is the surface parameterized by $r=langle 2uv,u^2−v^2,u^2+v^2rangle$ with $u^2+v^2leq16$. So, your entire surface is given by this parametrization
    – DiegoMath
    Nov 22 at 21:16








  • 1




    For example, if your surface $S$ is given by $r=langle u,v,u+vrangle$ where $0leq uleq 1$ and $0leq vleq 1$, then the surface is a piece of a plane and this is the entire surface
    – DiegoMath
    Nov 22 at 21:19
















So $S$ is not the entire surface?
– Art
Nov 22 at 21:07




So $S$ is not the entire surface?
– Art
Nov 22 at 21:07












$S$ is given by the parametrization. What do you mean with entire surface?
– DiegoMath
Nov 22 at 21:12






$S$ is given by the parametrization. What do you mean with entire surface?
– DiegoMath
Nov 22 at 21:12














The limits for S in $intint_S$ are not for the entire surface?
– Art
Nov 22 at 21:14






The limits for S in $intint_S$ are not for the entire surface?
– Art
Nov 22 at 21:14






1




1




You write this: where $S$ is the surface parameterized by $r=langle 2uv,u^2−v^2,u^2+v^2rangle$ with $u^2+v^2leq16$. So, your entire surface is given by this parametrization
– DiegoMath
Nov 22 at 21:16






You write this: where $S$ is the surface parameterized by $r=langle 2uv,u^2−v^2,u^2+v^2rangle$ with $u^2+v^2leq16$. So, your entire surface is given by this parametrization
– DiegoMath
Nov 22 at 21:16






1




1




For example, if your surface $S$ is given by $r=langle u,v,u+vrangle$ where $0leq uleq 1$ and $0leq vleq 1$, then the surface is a piece of a plane and this is the entire surface
– DiegoMath
Nov 22 at 21:19




For example, if your surface $S$ is given by $r=langle u,v,u+vrangle$ where $0leq uleq 1$ and $0leq vleq 1$, then the surface is a piece of a plane and this is the entire surface
– DiegoMath
Nov 22 at 21:19


















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%2f3009653%2fhow-to-evaluate-a-parameterized-surface-integral%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

Plaza Victoria

In PowerPoint, is there a keyboard shortcut for bulleted / numbered list?

How to put 3 figures in Latex with 2 figures side by side and 1 below these side by side images but in...