If $a$ and $b$ are constants, calculate the definite integral












3












$begingroup$


$$int_{-infty}^{+infty} F(x-b) f(x-a) dx$$



$$f(x) = exp(-x-e^{-x}), qquad x in (-infty, +infty)$$



$$F(x) = int_{-infty}^x f(t) dt$$



I calculated already the integral of $F(x)$, which is $exp(-e^{-x})$, but I am stuck on the other one, I have no idea how to calculate the integral of $F(x-a)f(x-b)$.










share|cite|improve this question











$endgroup$












  • $begingroup$
    Here's a MathJax tutorial :)
    $endgroup$
    – Shaun
    Dec 28 '18 at 8:26
















3












$begingroup$


$$int_{-infty}^{+infty} F(x-b) f(x-a) dx$$



$$f(x) = exp(-x-e^{-x}), qquad x in (-infty, +infty)$$



$$F(x) = int_{-infty}^x f(t) dt$$



I calculated already the integral of $F(x)$, which is $exp(-e^{-x})$, but I am stuck on the other one, I have no idea how to calculate the integral of $F(x-a)f(x-b)$.










share|cite|improve this question











$endgroup$












  • $begingroup$
    Here's a MathJax tutorial :)
    $endgroup$
    – Shaun
    Dec 28 '18 at 8:26














3












3








3


2



$begingroup$


$$int_{-infty}^{+infty} F(x-b) f(x-a) dx$$



$$f(x) = exp(-x-e^{-x}), qquad x in (-infty, +infty)$$



$$F(x) = int_{-infty}^x f(t) dt$$



I calculated already the integral of $F(x)$, which is $exp(-e^{-x})$, but I am stuck on the other one, I have no idea how to calculate the integral of $F(x-a)f(x-b)$.










share|cite|improve this question











$endgroup$




$$int_{-infty}^{+infty} F(x-b) f(x-a) dx$$



$$f(x) = exp(-x-e^{-x}), qquad x in (-infty, +infty)$$



$$F(x) = int_{-infty}^x f(t) dt$$



I calculated already the integral of $F(x)$, which is $exp(-e^{-x})$, but I am stuck on the other one, I have no idea how to calculate the integral of $F(x-a)f(x-b)$.







integration






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 28 '18 at 8:39









Rócherz

2,9863821




2,9863821










asked Dec 28 '18 at 8:22









user10471408user10471408

162




162












  • $begingroup$
    Here's a MathJax tutorial :)
    $endgroup$
    – Shaun
    Dec 28 '18 at 8:26


















  • $begingroup$
    Here's a MathJax tutorial :)
    $endgroup$
    – Shaun
    Dec 28 '18 at 8:26
















$begingroup$
Here's a MathJax tutorial :)
$endgroup$
– Shaun
Dec 28 '18 at 8:26




$begingroup$
Here's a MathJax tutorial :)
$endgroup$
– Shaun
Dec 28 '18 at 8:26










1 Answer
1






active

oldest

votes


















0












$begingroup$

$$int_{-infty}^{infty}F(a-b)f(x-a)dx=int_{-infty}^{infty}e^{-e^{-(x-b)}} e^{-(x-a)} e^{-e^{-(x-a)}} dx=$$



$Rightarrow e^{a} int_{-infty}^{infty} e^{-e^{-x}({e^{b}+e^{a}})} e^{-x} dx$



Now Let, $-e^{-x}=t, rightarrow e^{-x} dx =dt$



$Rightarrow e^{a} int_{-infty}^{0} e^{t{(e^{a}+e^{b}})} dt~~$



$Rightarrow frac{e^a}{e^{a}+e^{b}}.$






share|cite|improve this answer











$endgroup$













    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%2f3054679%2fif-a-and-b-are-constants-calculate-the-definite-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









    0












    $begingroup$

    $$int_{-infty}^{infty}F(a-b)f(x-a)dx=int_{-infty}^{infty}e^{-e^{-(x-b)}} e^{-(x-a)} e^{-e^{-(x-a)}} dx=$$



    $Rightarrow e^{a} int_{-infty}^{infty} e^{-e^{-x}({e^{b}+e^{a}})} e^{-x} dx$



    Now Let, $-e^{-x}=t, rightarrow e^{-x} dx =dt$



    $Rightarrow e^{a} int_{-infty}^{0} e^{t{(e^{a}+e^{b}})} dt~~$



    $Rightarrow frac{e^a}{e^{a}+e^{b}}.$






    share|cite|improve this answer











    $endgroup$


















      0












      $begingroup$

      $$int_{-infty}^{infty}F(a-b)f(x-a)dx=int_{-infty}^{infty}e^{-e^{-(x-b)}} e^{-(x-a)} e^{-e^{-(x-a)}} dx=$$



      $Rightarrow e^{a} int_{-infty}^{infty} e^{-e^{-x}({e^{b}+e^{a}})} e^{-x} dx$



      Now Let, $-e^{-x}=t, rightarrow e^{-x} dx =dt$



      $Rightarrow e^{a} int_{-infty}^{0} e^{t{(e^{a}+e^{b}})} dt~~$



      $Rightarrow frac{e^a}{e^{a}+e^{b}}.$






      share|cite|improve this answer











      $endgroup$
















        0












        0








        0





        $begingroup$

        $$int_{-infty}^{infty}F(a-b)f(x-a)dx=int_{-infty}^{infty}e^{-e^{-(x-b)}} e^{-(x-a)} e^{-e^{-(x-a)}} dx=$$



        $Rightarrow e^{a} int_{-infty}^{infty} e^{-e^{-x}({e^{b}+e^{a}})} e^{-x} dx$



        Now Let, $-e^{-x}=t, rightarrow e^{-x} dx =dt$



        $Rightarrow e^{a} int_{-infty}^{0} e^{t{(e^{a}+e^{b}})} dt~~$



        $Rightarrow frac{e^a}{e^{a}+e^{b}}.$






        share|cite|improve this answer











        $endgroup$



        $$int_{-infty}^{infty}F(a-b)f(x-a)dx=int_{-infty}^{infty}e^{-e^{-(x-b)}} e^{-(x-a)} e^{-e^{-(x-a)}} dx=$$



        $Rightarrow e^{a} int_{-infty}^{infty} e^{-e^{-x}({e^{b}+e^{a}})} e^{-x} dx$



        Now Let, $-e^{-x}=t, rightarrow e^{-x} dx =dt$



        $Rightarrow e^{a} int_{-infty}^{0} e^{t{(e^{a}+e^{b}})} dt~~$



        $Rightarrow frac{e^a}{e^{a}+e^{b}}.$







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Dec 28 '18 at 19:02

























        answered Dec 28 '18 at 10:05









        Sachin KumarSachin Kumar

        20519




        20519






























            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%2f3054679%2fif-a-and-b-are-constants-calculate-the-definite-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

            Wiesbaden

            Marschland

            Dieringhausen