Improper integral outside the domain of the function












0












$begingroup$


Improper Integral



Wolfram Alpha Answer



Obviously improper as the limits run outside the domain of the function. But does it converge? Any machine algorithm I feed this to says it does, and will provide a complex number as the answer. The definition of convergence relies on the limit existing and being finite - which apparently is the case in this instance. But how can I explain that it technically converges when the function isn't even defined on negatives?



Or perhaps is the function defined on negatives when we include the complex domain? It's kind of freaking me out that I can't get any machine algorithm to tell me this diverges...










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    If it makes you feel better, treat $intlimits_{-1}^2sqrt{x}~dx$ as $intlimits_{-1}^0sqrt{x}~dx~+intlimits_{0}^2sqrt{x}~dx$ and recognize that assuming you allow for complex numbers that $intlimits_{-1}^0 sqrt{x}~dx = intlimits_0^1icdotsqrt{x}~dx$. If you don't allow for complex numbers, then the result will of course be undefined.
    $endgroup$
    – JMoravitz
    Jan 11 at 4:25












  • $begingroup$
    OK JM, thank you - Will throw an asterisk in there -->Diverges *(unless we allow for complex numbers...)
    $endgroup$
    – Michael Schuster
    Jan 11 at 4:32


















0












$begingroup$


Improper Integral



Wolfram Alpha Answer



Obviously improper as the limits run outside the domain of the function. But does it converge? Any machine algorithm I feed this to says it does, and will provide a complex number as the answer. The definition of convergence relies on the limit existing and being finite - which apparently is the case in this instance. But how can I explain that it technically converges when the function isn't even defined on negatives?



Or perhaps is the function defined on negatives when we include the complex domain? It's kind of freaking me out that I can't get any machine algorithm to tell me this diverges...










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    If it makes you feel better, treat $intlimits_{-1}^2sqrt{x}~dx$ as $intlimits_{-1}^0sqrt{x}~dx~+intlimits_{0}^2sqrt{x}~dx$ and recognize that assuming you allow for complex numbers that $intlimits_{-1}^0 sqrt{x}~dx = intlimits_0^1icdotsqrt{x}~dx$. If you don't allow for complex numbers, then the result will of course be undefined.
    $endgroup$
    – JMoravitz
    Jan 11 at 4:25












  • $begingroup$
    OK JM, thank you - Will throw an asterisk in there -->Diverges *(unless we allow for complex numbers...)
    $endgroup$
    – Michael Schuster
    Jan 11 at 4:32
















0












0








0





$begingroup$


Improper Integral



Wolfram Alpha Answer



Obviously improper as the limits run outside the domain of the function. But does it converge? Any machine algorithm I feed this to says it does, and will provide a complex number as the answer. The definition of convergence relies on the limit existing and being finite - which apparently is the case in this instance. But how can I explain that it technically converges when the function isn't even defined on negatives?



Or perhaps is the function defined on negatives when we include the complex domain? It's kind of freaking me out that I can't get any machine algorithm to tell me this diverges...










share|cite|improve this question









$endgroup$




Improper Integral



Wolfram Alpha Answer



Obviously improper as the limits run outside the domain of the function. But does it converge? Any machine algorithm I feed this to says it does, and will provide a complex number as the answer. The definition of convergence relies on the limit existing and being finite - which apparently is the case in this instance. But how can I explain that it technically converges when the function isn't even defined on negatives?



Or perhaps is the function defined on negatives when we include the complex domain? It's kind of freaking me out that I can't get any machine algorithm to tell me this diverges...







integration






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 11 at 4:13









Michael SchusterMichael Schuster

1




1








  • 1




    $begingroup$
    If it makes you feel better, treat $intlimits_{-1}^2sqrt{x}~dx$ as $intlimits_{-1}^0sqrt{x}~dx~+intlimits_{0}^2sqrt{x}~dx$ and recognize that assuming you allow for complex numbers that $intlimits_{-1}^0 sqrt{x}~dx = intlimits_0^1icdotsqrt{x}~dx$. If you don't allow for complex numbers, then the result will of course be undefined.
    $endgroup$
    – JMoravitz
    Jan 11 at 4:25












  • $begingroup$
    OK JM, thank you - Will throw an asterisk in there -->Diverges *(unless we allow for complex numbers...)
    $endgroup$
    – Michael Schuster
    Jan 11 at 4:32
















  • 1




    $begingroup$
    If it makes you feel better, treat $intlimits_{-1}^2sqrt{x}~dx$ as $intlimits_{-1}^0sqrt{x}~dx~+intlimits_{0}^2sqrt{x}~dx$ and recognize that assuming you allow for complex numbers that $intlimits_{-1}^0 sqrt{x}~dx = intlimits_0^1icdotsqrt{x}~dx$. If you don't allow for complex numbers, then the result will of course be undefined.
    $endgroup$
    – JMoravitz
    Jan 11 at 4:25












  • $begingroup$
    OK JM, thank you - Will throw an asterisk in there -->Diverges *(unless we allow for complex numbers...)
    $endgroup$
    – Michael Schuster
    Jan 11 at 4:32










1




1




$begingroup$
If it makes you feel better, treat $intlimits_{-1}^2sqrt{x}~dx$ as $intlimits_{-1}^0sqrt{x}~dx~+intlimits_{0}^2sqrt{x}~dx$ and recognize that assuming you allow for complex numbers that $intlimits_{-1}^0 sqrt{x}~dx = intlimits_0^1icdotsqrt{x}~dx$. If you don't allow for complex numbers, then the result will of course be undefined.
$endgroup$
– JMoravitz
Jan 11 at 4:25






$begingroup$
If it makes you feel better, treat $intlimits_{-1}^2sqrt{x}~dx$ as $intlimits_{-1}^0sqrt{x}~dx~+intlimits_{0}^2sqrt{x}~dx$ and recognize that assuming you allow for complex numbers that $intlimits_{-1}^0 sqrt{x}~dx = intlimits_0^1icdotsqrt{x}~dx$. If you don't allow for complex numbers, then the result will of course be undefined.
$endgroup$
– JMoravitz
Jan 11 at 4:25














$begingroup$
OK JM, thank you - Will throw an asterisk in there -->Diverges *(unless we allow for complex numbers...)
$endgroup$
– Michael Schuster
Jan 11 at 4:32






$begingroup$
OK JM, thank you - Will throw an asterisk in there -->Diverges *(unless we allow for complex numbers...)
$endgroup$
– Michael Schuster
Jan 11 at 4:32












0






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',
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%2f3069471%2fimproper-integral-outside-the-domain-of-the-function%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3069471%2fimproper-integral-outside-the-domain-of-the-function%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

MongoDB - Not Authorized To Execute Command

in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith

How to fix TextFormField cause rebuild widget in Flutter