Complex roots, conjugated complex numbers











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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 $z=0$.










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















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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






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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










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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























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    up vote
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    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

        89.4k74495




        89.4k74495






























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