Calculating a periodic signal (way of solving this)?












0














I created my own examples so i can have the gist of how to solve the real ones that my homework needs so here we go:



$$x(t)=sum_{n=-infty}^infty Pileft({t-4nover2}right) + sum_{n=-infty}^infty Π{(t-4n)} $$



So i want to find if this singal is periodic and what it's period, can i have a step by step solution (more like understanding)?



What concernes me is how i tackle the sums.










share|cite|improve this question
























  • What is $Pi?$ Do you mean the number $pi?$
    – saulspatz
    Dec 26 '18 at 16:47










  • no by Π i mean the rectangular function en.wikipedia.org/wiki/Rectangular_function
    – Agaeus
    Dec 26 '18 at 18:20










  • Okay, what about $Πfrac{(t-4n)}{(2)}?$ Is that supposed to be $$Pileft({t-4nover2}right)?$$
    – saulspatz
    Dec 26 '18 at 20:46












  • well yeah that's it saulspatz.
    – Agaeus
    Dec 26 '18 at 21:55






  • 1




    The infinite sums are not truly infinite. For any particular $t$, only a finite number (a very low finite number) of the terms are non-zero. So to find the value for $t$, just sum up those few terms. And as a hint, consider what happens if you replace the index $n$ with a new index $m = n+1$.
    – Paul Sinclair
    Dec 27 '18 at 1:31
















0














I created my own examples so i can have the gist of how to solve the real ones that my homework needs so here we go:



$$x(t)=sum_{n=-infty}^infty Pileft({t-4nover2}right) + sum_{n=-infty}^infty Π{(t-4n)} $$



So i want to find if this singal is periodic and what it's period, can i have a step by step solution (more like understanding)?



What concernes me is how i tackle the sums.










share|cite|improve this question
























  • What is $Pi?$ Do you mean the number $pi?$
    – saulspatz
    Dec 26 '18 at 16:47










  • no by Π i mean the rectangular function en.wikipedia.org/wiki/Rectangular_function
    – Agaeus
    Dec 26 '18 at 18:20










  • Okay, what about $Πfrac{(t-4n)}{(2)}?$ Is that supposed to be $$Pileft({t-4nover2}right)?$$
    – saulspatz
    Dec 26 '18 at 20:46












  • well yeah that's it saulspatz.
    – Agaeus
    Dec 26 '18 at 21:55






  • 1




    The infinite sums are not truly infinite. For any particular $t$, only a finite number (a very low finite number) of the terms are non-zero. So to find the value for $t$, just sum up those few terms. And as a hint, consider what happens if you replace the index $n$ with a new index $m = n+1$.
    – Paul Sinclair
    Dec 27 '18 at 1:31














0












0








0







I created my own examples so i can have the gist of how to solve the real ones that my homework needs so here we go:



$$x(t)=sum_{n=-infty}^infty Pileft({t-4nover2}right) + sum_{n=-infty}^infty Π{(t-4n)} $$



So i want to find if this singal is periodic and what it's period, can i have a step by step solution (more like understanding)?



What concernes me is how i tackle the sums.










share|cite|improve this question















I created my own examples so i can have the gist of how to solve the real ones that my homework needs so here we go:



$$x(t)=sum_{n=-infty}^infty Pileft({t-4nover2}right) + sum_{n=-infty}^infty Π{(t-4n)} $$



So i want to find if this singal is periodic and what it's period, can i have a step by step solution (more like understanding)?



What concernes me is how i tackle the sums.







fourier-analysis fourier-transform signal-processing periodic-functions






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 26 '18 at 22:34









saulspatz

14k21329




14k21329










asked Dec 26 '18 at 14:09









Agaeus

626




626












  • What is $Pi?$ Do you mean the number $pi?$
    – saulspatz
    Dec 26 '18 at 16:47










  • no by Π i mean the rectangular function en.wikipedia.org/wiki/Rectangular_function
    – Agaeus
    Dec 26 '18 at 18:20










  • Okay, what about $Πfrac{(t-4n)}{(2)}?$ Is that supposed to be $$Pileft({t-4nover2}right)?$$
    – saulspatz
    Dec 26 '18 at 20:46












  • well yeah that's it saulspatz.
    – Agaeus
    Dec 26 '18 at 21:55






  • 1




    The infinite sums are not truly infinite. For any particular $t$, only a finite number (a very low finite number) of the terms are non-zero. So to find the value for $t$, just sum up those few terms. And as a hint, consider what happens if you replace the index $n$ with a new index $m = n+1$.
    – Paul Sinclair
    Dec 27 '18 at 1:31


















  • What is $Pi?$ Do you mean the number $pi?$
    – saulspatz
    Dec 26 '18 at 16:47










  • no by Π i mean the rectangular function en.wikipedia.org/wiki/Rectangular_function
    – Agaeus
    Dec 26 '18 at 18:20










  • Okay, what about $Πfrac{(t-4n)}{(2)}?$ Is that supposed to be $$Pileft({t-4nover2}right)?$$
    – saulspatz
    Dec 26 '18 at 20:46












  • well yeah that's it saulspatz.
    – Agaeus
    Dec 26 '18 at 21:55






  • 1




    The infinite sums are not truly infinite. For any particular $t$, only a finite number (a very low finite number) of the terms are non-zero. So to find the value for $t$, just sum up those few terms. And as a hint, consider what happens if you replace the index $n$ with a new index $m = n+1$.
    – Paul Sinclair
    Dec 27 '18 at 1:31
















What is $Pi?$ Do you mean the number $pi?$
– saulspatz
Dec 26 '18 at 16:47




What is $Pi?$ Do you mean the number $pi?$
– saulspatz
Dec 26 '18 at 16:47












no by Π i mean the rectangular function en.wikipedia.org/wiki/Rectangular_function
– Agaeus
Dec 26 '18 at 18:20




no by Π i mean the rectangular function en.wikipedia.org/wiki/Rectangular_function
– Agaeus
Dec 26 '18 at 18:20












Okay, what about $Πfrac{(t-4n)}{(2)}?$ Is that supposed to be $$Pileft({t-4nover2}right)?$$
– saulspatz
Dec 26 '18 at 20:46






Okay, what about $Πfrac{(t-4n)}{(2)}?$ Is that supposed to be $$Pileft({t-4nover2}right)?$$
– saulspatz
Dec 26 '18 at 20:46














well yeah that's it saulspatz.
– Agaeus
Dec 26 '18 at 21:55




well yeah that's it saulspatz.
– Agaeus
Dec 26 '18 at 21:55




1




1




The infinite sums are not truly infinite. For any particular $t$, only a finite number (a very low finite number) of the terms are non-zero. So to find the value for $t$, just sum up those few terms. And as a hint, consider what happens if you replace the index $n$ with a new index $m = n+1$.
– Paul Sinclair
Dec 27 '18 at 1:31




The infinite sums are not truly infinite. For any particular $t$, only a finite number (a very low finite number) of the terms are non-zero. So to find the value for $t$, just sum up those few terms. And as a hint, consider what happens if you replace the index $n$ with a new index $m = n+1$.
– Paul Sinclair
Dec 27 '18 at 1:31










1 Answer
1






active

oldest

votes


















0














HINT: Let be $f(t)=Pi(t/2)+Pi(t)$. So we have
$$
x(t)=sum_{n=-infty}^infty f(t-4n)
$$

Can you see that $x(t)$ is periodic with period $T=4$?






share|cite|improve this answer





















    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%2f3052969%2fcalculating-a-periodic-signal-way-of-solving-this%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














    HINT: Let be $f(t)=Pi(t/2)+Pi(t)$. So we have
    $$
    x(t)=sum_{n=-infty}^infty f(t-4n)
    $$

    Can you see that $x(t)$ is periodic with period $T=4$?






    share|cite|improve this answer


























      0














      HINT: Let be $f(t)=Pi(t/2)+Pi(t)$. So we have
      $$
      x(t)=sum_{n=-infty}^infty f(t-4n)
      $$

      Can you see that $x(t)$ is periodic with period $T=4$?






      share|cite|improve this answer
























        0












        0








        0






        HINT: Let be $f(t)=Pi(t/2)+Pi(t)$. So we have
        $$
        x(t)=sum_{n=-infty}^infty f(t-4n)
        $$

        Can you see that $x(t)$ is periodic with period $T=4$?






        share|cite|improve this answer












        HINT: Let be $f(t)=Pi(t/2)+Pi(t)$. So we have
        $$
        x(t)=sum_{n=-infty}^infty f(t-4n)
        $$

        Can you see that $x(t)$ is periodic with period $T=4$?







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 3 at 21:57









        alexjo

        12.3k1329




        12.3k1329






























            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%2f3052969%2fcalculating-a-periodic-signal-way-of-solving-this%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

            1300-talet

            1300-talet

            Display a custom attribute below product name in the front-end Magento 1.9.3.8