Symmetries of a Hexagon












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I am having trouble with the following problem.



Let $D_{12} = <a,b:a^6=b^2=e, ba=a^5b>$, the dihedral group of order 12, describe the symmetries of a regular hexagon. $a$ denotes a rotation about the center by 60 degrees, and $b$ denotes a reflection across a diagonal connecting a pair of opposite vertices.



I need to find the centralizers $C_{D_{12}}(a)$, $C_{D_{12}}(b)$, as well as the center $Z(D_{12})$.



Clearly, each element of $D_{12}$ can be written in the form $a^ib^j$, with $0leq ileq5$, and $0leq jleq1$. To find the centralizers, I think I need to use the Orbit-Stabilizer Theorem, but I'm not sure how to find the center.










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    I am having trouble with the following problem.



    Let $D_{12} = <a,b:a^6=b^2=e, ba=a^5b>$, the dihedral group of order 12, describe the symmetries of a regular hexagon. $a$ denotes a rotation about the center by 60 degrees, and $b$ denotes a reflection across a diagonal connecting a pair of opposite vertices.



    I need to find the centralizers $C_{D_{12}}(a)$, $C_{D_{12}}(b)$, as well as the center $Z(D_{12})$.



    Clearly, each element of $D_{12}$ can be written in the form $a^ib^j$, with $0leq ileq5$, and $0leq jleq1$. To find the centralizers, I think I need to use the Orbit-Stabilizer Theorem, but I'm not sure how to find the center.










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      0







      I am having trouble with the following problem.



      Let $D_{12} = <a,b:a^6=b^2=e, ba=a^5b>$, the dihedral group of order 12, describe the symmetries of a regular hexagon. $a$ denotes a rotation about the center by 60 degrees, and $b$ denotes a reflection across a diagonal connecting a pair of opposite vertices.



      I need to find the centralizers $C_{D_{12}}(a)$, $C_{D_{12}}(b)$, as well as the center $Z(D_{12})$.



      Clearly, each element of $D_{12}$ can be written in the form $a^ib^j$, with $0leq ileq5$, and $0leq jleq1$. To find the centralizers, I think I need to use the Orbit-Stabilizer Theorem, but I'm not sure how to find the center.










      share|cite|improve this question













      I am having trouble with the following problem.



      Let $D_{12} = <a,b:a^6=b^2=e, ba=a^5b>$, the dihedral group of order 12, describe the symmetries of a regular hexagon. $a$ denotes a rotation about the center by 60 degrees, and $b$ denotes a reflection across a diagonal connecting a pair of opposite vertices.



      I need to find the centralizers $C_{D_{12}}(a)$, $C_{D_{12}}(b)$, as well as the center $Z(D_{12})$.



      Clearly, each element of $D_{12}$ can be written in the form $a^ib^j$, with $0leq ileq5$, and $0leq jleq1$. To find the centralizers, I think I need to use the Orbit-Stabilizer Theorem, but I'm not sure how to find the center.







      abstract-algebra






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      asked Nov 24 at 19:38









      jclay

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          Centralizer of rotation is all rotations, centralizer of reflection is itself and the identity element. Centralizer of $G$ is identity and rotation by $pi$.






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            Centralizer of rotation is all rotations, centralizer of reflection is itself and the identity element. Centralizer of $G$ is identity and rotation by $pi$.






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              Centralizer of rotation is all rotations, centralizer of reflection is itself and the identity element. Centralizer of $G$ is identity and rotation by $pi$.






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                Centralizer of rotation is all rotations, centralizer of reflection is itself and the identity element. Centralizer of $G$ is identity and rotation by $pi$.






                share|cite|improve this answer












                Centralizer of rotation is all rotations, centralizer of reflection is itself and the identity element. Centralizer of $G$ is identity and rotation by $pi$.







                share|cite|improve this answer












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                answered Nov 24 at 19:49









                mathnoob

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