How to compute a special double integral on a finite domain












0












$begingroup$


For any given integer $n>2$ and real constants $0leq aleq 1$ and $c>0$, I want to compute the integral:



$$ int _0^aint _0^afrac{(1+ c,x, y)^{n-2} (1+n,c, x, y)}{(1+x) (1+y)}, dx,dy $$



Wolfram Mathematica 11.3 does not give an answer.










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    Open the parentheses in the numerator to start with.
    $endgroup$
    – fedja
    Dec 1 '18 at 18:30
















0












$begingroup$


For any given integer $n>2$ and real constants $0leq aleq 1$ and $c>0$, I want to compute the integral:



$$ int _0^aint _0^afrac{(1+ c,x, y)^{n-2} (1+n,c, x, y)}{(1+x) (1+y)}, dx,dy $$



Wolfram Mathematica 11.3 does not give an answer.










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    Open the parentheses in the numerator to start with.
    $endgroup$
    – fedja
    Dec 1 '18 at 18:30














0












0








0





$begingroup$


For any given integer $n>2$ and real constants $0leq aleq 1$ and $c>0$, I want to compute the integral:



$$ int _0^aint _0^afrac{(1+ c,x, y)^{n-2} (1+n,c, x, y)}{(1+x) (1+y)}, dx,dy $$



Wolfram Mathematica 11.3 does not give an answer.










share|cite|improve this question









$endgroup$




For any given integer $n>2$ and real constants $0leq aleq 1$ and $c>0$, I want to compute the integral:



$$ int _0^aint _0^afrac{(1+ c,x, y)^{n-2} (1+n,c, x, y)}{(1+x) (1+y)}, dx,dy $$



Wolfram Mathematica 11.3 does not give an answer.







integration multivariable-calculus






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 1 '18 at 18:13









kaffeeaufkaffeeauf

14810




14810








  • 1




    $begingroup$
    Open the parentheses in the numerator to start with.
    $endgroup$
    – fedja
    Dec 1 '18 at 18:30














  • 1




    $begingroup$
    Open the parentheses in the numerator to start with.
    $endgroup$
    – fedja
    Dec 1 '18 at 18:30








1




1




$begingroup$
Open the parentheses in the numerator to start with.
$endgroup$
– fedja
Dec 1 '18 at 18:30




$begingroup$
Open the parentheses in the numerator to start with.
$endgroup$
– fedja
Dec 1 '18 at 18:30










1 Answer
1






active

oldest

votes


















1












$begingroup$

we have:
$$I=int_0^aint_0^afrac{(1+cxy)^{n-2}(1+ncxy)}{(1+x)(1+y)}dxdy$$
$$=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}+ncyx(1+cyx)^{n-2}}{(1+x)}dxdy$$
if we focus on the first one:
$$I_1=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}}{(1+x)}dxdy$$
this inside integral has no elementary derivative and neither do the others involved, so it appears that if there is a solution it will involve a double summation potentially






share|cite|improve this answer









$endgroup$













  • $begingroup$
    The inside integral could be expressed in terms of certain hypergeometric functions.
    $endgroup$
    – kaffeeauf
    Dec 1 '18 at 20:43











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%2f3021645%2fhow-to-compute-a-special-double-integral-on-a-finite-domain%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












$begingroup$

we have:
$$I=int_0^aint_0^afrac{(1+cxy)^{n-2}(1+ncxy)}{(1+x)(1+y)}dxdy$$
$$=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}+ncyx(1+cyx)^{n-2}}{(1+x)}dxdy$$
if we focus on the first one:
$$I_1=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}}{(1+x)}dxdy$$
this inside integral has no elementary derivative and neither do the others involved, so it appears that if there is a solution it will involve a double summation potentially






share|cite|improve this answer









$endgroup$













  • $begingroup$
    The inside integral could be expressed in terms of certain hypergeometric functions.
    $endgroup$
    – kaffeeauf
    Dec 1 '18 at 20:43
















1












$begingroup$

we have:
$$I=int_0^aint_0^afrac{(1+cxy)^{n-2}(1+ncxy)}{(1+x)(1+y)}dxdy$$
$$=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}+ncyx(1+cyx)^{n-2}}{(1+x)}dxdy$$
if we focus on the first one:
$$I_1=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}}{(1+x)}dxdy$$
this inside integral has no elementary derivative and neither do the others involved, so it appears that if there is a solution it will involve a double summation potentially






share|cite|improve this answer









$endgroup$













  • $begingroup$
    The inside integral could be expressed in terms of certain hypergeometric functions.
    $endgroup$
    – kaffeeauf
    Dec 1 '18 at 20:43














1












1








1





$begingroup$

we have:
$$I=int_0^aint_0^afrac{(1+cxy)^{n-2}(1+ncxy)}{(1+x)(1+y)}dxdy$$
$$=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}+ncyx(1+cyx)^{n-2}}{(1+x)}dxdy$$
if we focus on the first one:
$$I_1=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}}{(1+x)}dxdy$$
this inside integral has no elementary derivative and neither do the others involved, so it appears that if there is a solution it will involve a double summation potentially






share|cite|improve this answer









$endgroup$



we have:
$$I=int_0^aint_0^afrac{(1+cxy)^{n-2}(1+ncxy)}{(1+x)(1+y)}dxdy$$
$$=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}+ncyx(1+cyx)^{n-2}}{(1+x)}dxdy$$
if we focus on the first one:
$$I_1=int_0^afrac{1}{(1+y)}int_0^afrac{(1+cyx)^{n-2}}{(1+x)}dxdy$$
this inside integral has no elementary derivative and neither do the others involved, so it appears that if there is a solution it will involve a double summation potentially







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Dec 1 '18 at 19:02









Henry LeeHenry Lee

1,857219




1,857219












  • $begingroup$
    The inside integral could be expressed in terms of certain hypergeometric functions.
    $endgroup$
    – kaffeeauf
    Dec 1 '18 at 20:43


















  • $begingroup$
    The inside integral could be expressed in terms of certain hypergeometric functions.
    $endgroup$
    – kaffeeauf
    Dec 1 '18 at 20:43
















$begingroup$
The inside integral could be expressed in terms of certain hypergeometric functions.
$endgroup$
– kaffeeauf
Dec 1 '18 at 20:43




$begingroup$
The inside integral could be expressed in terms of certain hypergeometric functions.
$endgroup$
– kaffeeauf
Dec 1 '18 at 20:43


















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%2f3021645%2fhow-to-compute-a-special-double-integral-on-a-finite-domain%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

Ellipse (mathématiques)

Quarter-circle Tiles

Mont Emei