Complex roots, conjugated complex numbers











up vote
0
down vote

favorite
1












Knowing that $$ cosfrac{pi}{8}=frac {1}{2}sqrt{2+sqrt{2}},$$
find all roots of these equations:



$2 overline z=z^7$,



$32 overline z=z^7$,



$128 overline z+z^7=0$.



Only those which have solutions different from $z=0$.










share|cite|improve this question
























  • Sorry my bad I added cos
    – B. Czostek
    Nov 18 at 11:21















up vote
0
down vote

favorite
1












Knowing that $$ cosfrac{pi}{8}=frac {1}{2}sqrt{2+sqrt{2}},$$
find all roots of these equations:



$2 overline z=z^7$,



$32 overline z=z^7$,



$128 overline z+z^7=0$.



Only those which have solutions different from $z=0$.










share|cite|improve this question
























  • Sorry my bad I added cos
    – B. Czostek
    Nov 18 at 11:21













up vote
0
down vote

favorite
1









up vote
0
down vote

favorite
1






1





Knowing that $$ cosfrac{pi}{8}=frac {1}{2}sqrt{2+sqrt{2}},$$
find all roots of these equations:



$2 overline z=z^7$,



$32 overline z=z^7$,



$128 overline z+z^7=0$.



Only those which have solutions different from $z=0$.










share|cite|improve this question















Knowing that $$ cosfrac{pi}{8}=frac {1}{2}sqrt{2+sqrt{2}},$$
find all roots of these equations:



$2 overline z=z^7$,



$32 overline z=z^7$,



$128 overline z+z^7=0$.



Only those which have solutions different from $z=0$.







complex-numbers






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 18 at 11:20

























asked Nov 18 at 11:09









B. Czostek

294




294












  • Sorry my bad I added cos
    – B. Czostek
    Nov 18 at 11:21


















  • Sorry my bad I added cos
    – B. Czostek
    Nov 18 at 11:21
















Sorry my bad I added cos
– B. Czostek
Nov 18 at 11:21




Sorry my bad I added cos
– B. Czostek
Nov 18 at 11:21










1 Answer
1






active

oldest

votes

















up vote
0
down vote













For the first one we have that



$$2overline z=z^7 implies 2overline zz=z^8 implies z^8=2|z|^2implies |z|^6=2 quad z=sqrt[6] 2$$



then we need to solve



$$z^8=2sqrt[3] 2$$



and similarly for the others.



The solution seems not related to $cos frac{pi}8$.






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%2f3003404%2fcomplex-roots-conjugated-complex-numbers%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













    For the first one we have that



    $$2overline z=z^7 implies 2overline zz=z^8 implies z^8=2|z|^2implies |z|^6=2 quad z=sqrt[6] 2$$



    then we need to solve



    $$z^8=2sqrt[3] 2$$



    and similarly for the others.



    The solution seems not related to $cos frac{pi}8$.






    share|cite|improve this answer



























      up vote
      0
      down vote













      For the first one we have that



      $$2overline z=z^7 implies 2overline zz=z^8 implies z^8=2|z|^2implies |z|^6=2 quad z=sqrt[6] 2$$



      then we need to solve



      $$z^8=2sqrt[3] 2$$



      and similarly for the others.



      The solution seems not related to $cos frac{pi}8$.






      share|cite|improve this answer

























        up vote
        0
        down vote










        up vote
        0
        down vote









        For the first one we have that



        $$2overline z=z^7 implies 2overline zz=z^8 implies z^8=2|z|^2implies |z|^6=2 quad z=sqrt[6] 2$$



        then we need to solve



        $$z^8=2sqrt[3] 2$$



        and similarly for the others.



        The solution seems not related to $cos frac{pi}8$.






        share|cite|improve this answer














        For the first one we have that



        $$2overline z=z^7 implies 2overline zz=z^8 implies z^8=2|z|^2implies |z|^6=2 quad z=sqrt[6] 2$$



        then we need to solve



        $$z^8=2sqrt[3] 2$$



        and similarly for the others.



        The solution seems not related to $cos frac{pi}8$.







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Nov 18 at 11:26

























        answered Nov 18 at 11:19









        gimusi

        90.7k74495




        90.7k74495






























            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%2f3003404%2fcomplex-roots-conjugated-complex-numbers%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

            How to change which sound is reproduced for terminal bell?

            Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents

            Can I use Tabulator js library in my java Spring + Thymeleaf project?