Find the volume bounded by the paraboloid $x^2+y^2=az$, the cylinder $x^2+y^2=2ay$ and the plane $z=0$












0












$begingroup$


Find the volume bounded by the paraboloid $x^2+y^2=az$, the cylinder $x^2+y^2=2ay$ and the plane $z=0$



My work



Changing to cylindrical coordinates



For Paraboloid



$$x^2+y^2=az;;;implies r^2=az;;;implies z=frac{r^2}{a}$$



For the cylinder



$$x^2+y^2=2ay;;;implies r=2a sin theta$$



Since this volume lies only in first two quadrants $theta$ goes from $0$ to $pi$



Volume=$int_{theta=0}^{pi}int_{r=0}^{2asin theta}int_{z=0}^{r^2/a}r dr dtheta dz$










share|cite|improve this question











$endgroup$












  • $begingroup$
    Well, $yin[0..2a], xin[-sqrt{2ay-y^2}..sqrt{2ay-y^2}], zin[0..(x^2+y^2)/a]$ but a change of variables might be better.
    $endgroup$
    – Graham Kemp
    Aug 19 '17 at 9:25
















0












$begingroup$


Find the volume bounded by the paraboloid $x^2+y^2=az$, the cylinder $x^2+y^2=2ay$ and the plane $z=0$



My work



Changing to cylindrical coordinates



For Paraboloid



$$x^2+y^2=az;;;implies r^2=az;;;implies z=frac{r^2}{a}$$



For the cylinder



$$x^2+y^2=2ay;;;implies r=2a sin theta$$



Since this volume lies only in first two quadrants $theta$ goes from $0$ to $pi$



Volume=$int_{theta=0}^{pi}int_{r=0}^{2asin theta}int_{z=0}^{r^2/a}r dr dtheta dz$










share|cite|improve this question











$endgroup$












  • $begingroup$
    Well, $yin[0..2a], xin[-sqrt{2ay-y^2}..sqrt{2ay-y^2}], zin[0..(x^2+y^2)/a]$ but a change of variables might be better.
    $endgroup$
    – Graham Kemp
    Aug 19 '17 at 9:25














0












0








0


0



$begingroup$


Find the volume bounded by the paraboloid $x^2+y^2=az$, the cylinder $x^2+y^2=2ay$ and the plane $z=0$



My work



Changing to cylindrical coordinates



For Paraboloid



$$x^2+y^2=az;;;implies r^2=az;;;implies z=frac{r^2}{a}$$



For the cylinder



$$x^2+y^2=2ay;;;implies r=2a sin theta$$



Since this volume lies only in first two quadrants $theta$ goes from $0$ to $pi$



Volume=$int_{theta=0}^{pi}int_{r=0}^{2asin theta}int_{z=0}^{r^2/a}r dr dtheta dz$










share|cite|improve this question











$endgroup$




Find the volume bounded by the paraboloid $x^2+y^2=az$, the cylinder $x^2+y^2=2ay$ and the plane $z=0$



My work



Changing to cylindrical coordinates



For Paraboloid



$$x^2+y^2=az;;;implies r^2=az;;;implies z=frac{r^2}{a}$$



For the cylinder



$$x^2+y^2=2ay;;;implies r=2a sin theta$$



Since this volume lies only in first two quadrants $theta$ goes from $0$ to $pi$



Volume=$int_{theta=0}^{pi}int_{r=0}^{2asin theta}int_{z=0}^{r^2/a}r dr dtheta dz$







multiple-integral






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Aug 22 '17 at 0:37







user467745

















asked Aug 19 '17 at 9:00









user467745user467745

239112




239112












  • $begingroup$
    Well, $yin[0..2a], xin[-sqrt{2ay-y^2}..sqrt{2ay-y^2}], zin[0..(x^2+y^2)/a]$ but a change of variables might be better.
    $endgroup$
    – Graham Kemp
    Aug 19 '17 at 9:25


















  • $begingroup$
    Well, $yin[0..2a], xin[-sqrt{2ay-y^2}..sqrt{2ay-y^2}], zin[0..(x^2+y^2)/a]$ but a change of variables might be better.
    $endgroup$
    – Graham Kemp
    Aug 19 '17 at 9:25
















$begingroup$
Well, $yin[0..2a], xin[-sqrt{2ay-y^2}..sqrt{2ay-y^2}], zin[0..(x^2+y^2)/a]$ but a change of variables might be better.
$endgroup$
– Graham Kemp
Aug 19 '17 at 9:25




$begingroup$
Well, $yin[0..2a], xin[-sqrt{2ay-y^2}..sqrt{2ay-y^2}], zin[0..(x^2+y^2)/a]$ but a change of variables might be better.
$endgroup$
– Graham Kemp
Aug 19 '17 at 9:25










1 Answer
1






active

oldest

votes


















0












$begingroup$

Using cylinder coordinate is the best way to solve this problem :
$$left{(rcostheta ,rsintheta +a ,z)mid theta in [0,2pi], rin[0,a], zin left[0,frac{2r^2+2arsin theta+a^2}{a}right]right}.$$






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Yes, it does look much easier. But what would be the limits in cartesian coords?
    $endgroup$
    – user467745
    Aug 19 '17 at 9:21










  • $begingroup$
    @user467745 : Something as $yin [0,2a]$, $xin [-sqrt{2a-(y-1)^2},sqrt{2a-(y-1)^2}]$ and $zin [0, frac{x^2}{a}+frac{y^2}{a}]$.
    $endgroup$
    – Surb
    Aug 19 '17 at 9:25










  • $begingroup$
    Just to cross check-the answer would be $pi a^3$, right?
    $endgroup$
    – user467745
    Aug 19 '17 at 10:27












  • $begingroup$
    @user467745: I'm not a computer ;-)
    $endgroup$
    – Surb
    Aug 19 '17 at 10:35










  • $begingroup$
    Did I imply that? I am sorry. Thanks for your time
    $endgroup$
    – user467745
    Aug 19 '17 at 10:53












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%2f2398981%2ffind-the-volume-bounded-by-the-paraboloid-x2y2-az-the-cylinder-x2y2-2a%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









0












$begingroup$

Using cylinder coordinate is the best way to solve this problem :
$$left{(rcostheta ,rsintheta +a ,z)mid theta in [0,2pi], rin[0,a], zin left[0,frac{2r^2+2arsin theta+a^2}{a}right]right}.$$






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Yes, it does look much easier. But what would be the limits in cartesian coords?
    $endgroup$
    – user467745
    Aug 19 '17 at 9:21










  • $begingroup$
    @user467745 : Something as $yin [0,2a]$, $xin [-sqrt{2a-(y-1)^2},sqrt{2a-(y-1)^2}]$ and $zin [0, frac{x^2}{a}+frac{y^2}{a}]$.
    $endgroup$
    – Surb
    Aug 19 '17 at 9:25










  • $begingroup$
    Just to cross check-the answer would be $pi a^3$, right?
    $endgroup$
    – user467745
    Aug 19 '17 at 10:27












  • $begingroup$
    @user467745: I'm not a computer ;-)
    $endgroup$
    – Surb
    Aug 19 '17 at 10:35










  • $begingroup$
    Did I imply that? I am sorry. Thanks for your time
    $endgroup$
    – user467745
    Aug 19 '17 at 10:53
















0












$begingroup$

Using cylinder coordinate is the best way to solve this problem :
$$left{(rcostheta ,rsintheta +a ,z)mid theta in [0,2pi], rin[0,a], zin left[0,frac{2r^2+2arsin theta+a^2}{a}right]right}.$$






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Yes, it does look much easier. But what would be the limits in cartesian coords?
    $endgroup$
    – user467745
    Aug 19 '17 at 9:21










  • $begingroup$
    @user467745 : Something as $yin [0,2a]$, $xin [-sqrt{2a-(y-1)^2},sqrt{2a-(y-1)^2}]$ and $zin [0, frac{x^2}{a}+frac{y^2}{a}]$.
    $endgroup$
    – Surb
    Aug 19 '17 at 9:25










  • $begingroup$
    Just to cross check-the answer would be $pi a^3$, right?
    $endgroup$
    – user467745
    Aug 19 '17 at 10:27












  • $begingroup$
    @user467745: I'm not a computer ;-)
    $endgroup$
    – Surb
    Aug 19 '17 at 10:35










  • $begingroup$
    Did I imply that? I am sorry. Thanks for your time
    $endgroup$
    – user467745
    Aug 19 '17 at 10:53














0












0








0





$begingroup$

Using cylinder coordinate is the best way to solve this problem :
$$left{(rcostheta ,rsintheta +a ,z)mid theta in [0,2pi], rin[0,a], zin left[0,frac{2r^2+2arsin theta+a^2}{a}right]right}.$$






share|cite|improve this answer











$endgroup$



Using cylinder coordinate is the best way to solve this problem :
$$left{(rcostheta ,rsintheta +a ,z)mid theta in [0,2pi], rin[0,a], zin left[0,frac{2r^2+2arsin theta+a^2}{a}right]right}.$$







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Aug 19 '17 at 15:43

























answered Aug 19 '17 at 9:15









SurbSurb

38.4k94478




38.4k94478












  • $begingroup$
    Yes, it does look much easier. But what would be the limits in cartesian coords?
    $endgroup$
    – user467745
    Aug 19 '17 at 9:21










  • $begingroup$
    @user467745 : Something as $yin [0,2a]$, $xin [-sqrt{2a-(y-1)^2},sqrt{2a-(y-1)^2}]$ and $zin [0, frac{x^2}{a}+frac{y^2}{a}]$.
    $endgroup$
    – Surb
    Aug 19 '17 at 9:25










  • $begingroup$
    Just to cross check-the answer would be $pi a^3$, right?
    $endgroup$
    – user467745
    Aug 19 '17 at 10:27












  • $begingroup$
    @user467745: I'm not a computer ;-)
    $endgroup$
    – Surb
    Aug 19 '17 at 10:35










  • $begingroup$
    Did I imply that? I am sorry. Thanks for your time
    $endgroup$
    – user467745
    Aug 19 '17 at 10:53


















  • $begingroup$
    Yes, it does look much easier. But what would be the limits in cartesian coords?
    $endgroup$
    – user467745
    Aug 19 '17 at 9:21










  • $begingroup$
    @user467745 : Something as $yin [0,2a]$, $xin [-sqrt{2a-(y-1)^2},sqrt{2a-(y-1)^2}]$ and $zin [0, frac{x^2}{a}+frac{y^2}{a}]$.
    $endgroup$
    – Surb
    Aug 19 '17 at 9:25










  • $begingroup$
    Just to cross check-the answer would be $pi a^3$, right?
    $endgroup$
    – user467745
    Aug 19 '17 at 10:27












  • $begingroup$
    @user467745: I'm not a computer ;-)
    $endgroup$
    – Surb
    Aug 19 '17 at 10:35










  • $begingroup$
    Did I imply that? I am sorry. Thanks for your time
    $endgroup$
    – user467745
    Aug 19 '17 at 10:53
















$begingroup$
Yes, it does look much easier. But what would be the limits in cartesian coords?
$endgroup$
– user467745
Aug 19 '17 at 9:21




$begingroup$
Yes, it does look much easier. But what would be the limits in cartesian coords?
$endgroup$
– user467745
Aug 19 '17 at 9:21












$begingroup$
@user467745 : Something as $yin [0,2a]$, $xin [-sqrt{2a-(y-1)^2},sqrt{2a-(y-1)^2}]$ and $zin [0, frac{x^2}{a}+frac{y^2}{a}]$.
$endgroup$
– Surb
Aug 19 '17 at 9:25




$begingroup$
@user467745 : Something as $yin [0,2a]$, $xin [-sqrt{2a-(y-1)^2},sqrt{2a-(y-1)^2}]$ and $zin [0, frac{x^2}{a}+frac{y^2}{a}]$.
$endgroup$
– Surb
Aug 19 '17 at 9:25












$begingroup$
Just to cross check-the answer would be $pi a^3$, right?
$endgroup$
– user467745
Aug 19 '17 at 10:27






$begingroup$
Just to cross check-the answer would be $pi a^3$, right?
$endgroup$
– user467745
Aug 19 '17 at 10:27














$begingroup$
@user467745: I'm not a computer ;-)
$endgroup$
– Surb
Aug 19 '17 at 10:35




$begingroup$
@user467745: I'm not a computer ;-)
$endgroup$
– Surb
Aug 19 '17 at 10:35












$begingroup$
Did I imply that? I am sorry. Thanks for your time
$endgroup$
– user467745
Aug 19 '17 at 10:53




$begingroup$
Did I imply that? I am sorry. Thanks for your time
$endgroup$
– user467745
Aug 19 '17 at 10:53


















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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2398981%2ffind-the-volume-bounded-by-the-paraboloid-x2y2-az-the-cylinder-x2y2-2a%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 to change which sound is reproduced for terminal bell?

Can I use Tabulator js library in my java Spring + Thymeleaf project?

Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents