Infinite non-periodic binary fraction











up vote
0
down vote

favorite












I have an infinite non-periodic binary fraction. For example:



$frac_1=0.101111011100110010001001010010000001001...$



Is it always true that $1-frac_1$ = non-periodic binary fraction?










share|cite|improve this question






















  • By non-periodic, I suppose you mean not "ultimately periodic". The answer is quite obviously yes. Notice that $1-frac_1$ has the same binary expansion where you switch $0$ and $1$.
    – Jean-Claude Arbaut
    Nov 19 at 19:54

















up vote
0
down vote

favorite












I have an infinite non-periodic binary fraction. For example:



$frac_1=0.101111011100110010001001010010000001001...$



Is it always true that $1-frac_1$ = non-periodic binary fraction?










share|cite|improve this question






















  • By non-periodic, I suppose you mean not "ultimately periodic". The answer is quite obviously yes. Notice that $1-frac_1$ has the same binary expansion where you switch $0$ and $1$.
    – Jean-Claude Arbaut
    Nov 19 at 19:54















up vote
0
down vote

favorite









up vote
0
down vote

favorite











I have an infinite non-periodic binary fraction. For example:



$frac_1=0.101111011100110010001001010010000001001...$



Is it always true that $1-frac_1$ = non-periodic binary fraction?










share|cite|improve this question













I have an infinite non-periodic binary fraction. For example:



$frac_1=0.101111011100110010001001010010000001001...$



Is it always true that $1-frac_1$ = non-periodic binary fraction?







fractions






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Nov 19 at 19:50









bvl

72




72












  • By non-periodic, I suppose you mean not "ultimately periodic". The answer is quite obviously yes. Notice that $1-frac_1$ has the same binary expansion where you switch $0$ and $1$.
    – Jean-Claude Arbaut
    Nov 19 at 19:54




















  • By non-periodic, I suppose you mean not "ultimately periodic". The answer is quite obviously yes. Notice that $1-frac_1$ has the same binary expansion where you switch $0$ and $1$.
    – Jean-Claude Arbaut
    Nov 19 at 19:54


















By non-periodic, I suppose you mean not "ultimately periodic". The answer is quite obviously yes. Notice that $1-frac_1$ has the same binary expansion where you switch $0$ and $1$.
– Jean-Claude Arbaut
Nov 19 at 19:54






By non-periodic, I suppose you mean not "ultimately periodic". The answer is quite obviously yes. Notice that $1-frac_1$ has the same binary expansion where you switch $0$ and $1$.
– Jean-Claude Arbaut
Nov 19 at 19:54












1 Answer
1






active

oldest

votes

















up vote
0
down vote



accepted










Well, yes. This is actually quite obvious.



If a fraction repeats (is periodic) then it is a fraction. If it's not, then it's not a fraction (that is, it's irrational).



Clearly, a number $q$ is a fraction if and only if $1-q$ is. Hence, if the digits of some number $q$ do not repeat, neither will the digits of $1-q$.



In fact, as pointed out in the comments, it's even easier to see it when you realize $1-q$ (if it's binary) is just $q$ with the digits flipped (changing $0$s into $1$s and vice versa). So, if $q$ doesn't repeat, neither will $1-q$.






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',
    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%2f3005431%2finfinite-non-periodic-binary-fraction%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








    up vote
    0
    down vote



    accepted










    Well, yes. This is actually quite obvious.



    If a fraction repeats (is periodic) then it is a fraction. If it's not, then it's not a fraction (that is, it's irrational).



    Clearly, a number $q$ is a fraction if and only if $1-q$ is. Hence, if the digits of some number $q$ do not repeat, neither will the digits of $1-q$.



    In fact, as pointed out in the comments, it's even easier to see it when you realize $1-q$ (if it's binary) is just $q$ with the digits flipped (changing $0$s into $1$s and vice versa). So, if $q$ doesn't repeat, neither will $1-q$.






    share|cite|improve this answer

























      up vote
      0
      down vote



      accepted










      Well, yes. This is actually quite obvious.



      If a fraction repeats (is periodic) then it is a fraction. If it's not, then it's not a fraction (that is, it's irrational).



      Clearly, a number $q$ is a fraction if and only if $1-q$ is. Hence, if the digits of some number $q$ do not repeat, neither will the digits of $1-q$.



      In fact, as pointed out in the comments, it's even easier to see it when you realize $1-q$ (if it's binary) is just $q$ with the digits flipped (changing $0$s into $1$s and vice versa). So, if $q$ doesn't repeat, neither will $1-q$.






      share|cite|improve this answer























        up vote
        0
        down vote



        accepted







        up vote
        0
        down vote



        accepted






        Well, yes. This is actually quite obvious.



        If a fraction repeats (is periodic) then it is a fraction. If it's not, then it's not a fraction (that is, it's irrational).



        Clearly, a number $q$ is a fraction if and only if $1-q$ is. Hence, if the digits of some number $q$ do not repeat, neither will the digits of $1-q$.



        In fact, as pointed out in the comments, it's even easier to see it when you realize $1-q$ (if it's binary) is just $q$ with the digits flipped (changing $0$s into $1$s and vice versa). So, if $q$ doesn't repeat, neither will $1-q$.






        share|cite|improve this answer












        Well, yes. This is actually quite obvious.



        If a fraction repeats (is periodic) then it is a fraction. If it's not, then it's not a fraction (that is, it's irrational).



        Clearly, a number $q$ is a fraction if and only if $1-q$ is. Hence, if the digits of some number $q$ do not repeat, neither will the digits of $1-q$.



        In fact, as pointed out in the comments, it's even easier to see it when you realize $1-q$ (if it's binary) is just $q$ with the digits flipped (changing $0$s into $1$s and vice versa). So, if $q$ doesn't repeat, neither will $1-q$.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Nov 19 at 19:59









        vrugtehagel

        10.7k1549




        10.7k1549






























            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%2f3005431%2finfinite-non-periodic-binary-fraction%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

            Bundesstraße 106

            Verónica Boquete

            Ida-Boy-Ed-Garten