Dimension of the field












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let $F$ be a field with $7^6$ elements and let $K$ be a subfield of $F$ with $49$ elements then the dimension of $F$ as a vector space over $K$ is...I don't know how to proceed anyone please help me!!!










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    $begingroup$


    let $F$ be a field with $7^6$ elements and let $K$ be a subfield of $F$ with $49$ elements then the dimension of $F$ as a vector space over $K$ is...I don't know how to proceed anyone please help me!!!










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    $endgroup$















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      1








      1





      $begingroup$


      let $F$ be a field with $7^6$ elements and let $K$ be a subfield of $F$ with $49$ elements then the dimension of $F$ as a vector space over $K$ is...I don't know how to proceed anyone please help me!!!










      share|cite|improve this question









      $endgroup$




      let $F$ be a field with $7^6$ elements and let $K$ be a subfield of $F$ with $49$ elements then the dimension of $F$ as a vector space over $K$ is...I don't know how to proceed anyone please help me!!!







      linear-algebra






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      asked Jan 5 at 0:12









      Gopi SGopi S

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          $begingroup$

          Let's say the dimension of $F$ as a vector space over $K$ is $n$. This means there is a basis of $F$ with a cardinality of $n$ elements. We will call this basis $f_1, f_2, ..., f_n$. By the definition of a basis, every element of $F$ can be expressed in the form of $k_1f_1+k_2f_2+...+k_nf_n$ for some $k_1,k_2,...,k_n in K$.



          Now, since $K$ has $49$ elements, there are $49$ possible values of $k_i$ for any $1leq i leq n$. Thus, there are $49$ choices for each $k_i$ and $n$ different $k_i$ variables, meaning there are $49^n$ possible values of $k_1f_1+k_2f_2+...+k_nf_n$. Thus, there are $49^n$ elements in the field $F$.



          Now, there are $7^6$ elements in the field $F$. Thus, we have the following equation:



          $$49^n=7^6rightarrow (7^2)^n=7^6rightarrow 7^{2n}=7^6rightarrow 2n=6rightarrow n=3$$



          Therefore, $F$ is a vector space of dimension $3$ over $K$.






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            $begingroup$

            Very simply, we have this formula, considering the prime subfield of $F$:
            $$underbrace{[F:mathbf F_7]}_{=,6}=[F:L]cdotunderbrace{[L:mathbf F_7]}_{=,2}$$






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              $begingroup$

              Let's say the dimension of $F$ as a vector space over $K$ is $n$. This means there is a basis of $F$ with a cardinality of $n$ elements. We will call this basis $f_1, f_2, ..., f_n$. By the definition of a basis, every element of $F$ can be expressed in the form of $k_1f_1+k_2f_2+...+k_nf_n$ for some $k_1,k_2,...,k_n in K$.



              Now, since $K$ has $49$ elements, there are $49$ possible values of $k_i$ for any $1leq i leq n$. Thus, there are $49$ choices for each $k_i$ and $n$ different $k_i$ variables, meaning there are $49^n$ possible values of $k_1f_1+k_2f_2+...+k_nf_n$. Thus, there are $49^n$ elements in the field $F$.



              Now, there are $7^6$ elements in the field $F$. Thus, we have the following equation:



              $$49^n=7^6rightarrow (7^2)^n=7^6rightarrow 7^{2n}=7^6rightarrow 2n=6rightarrow n=3$$



              Therefore, $F$ is a vector space of dimension $3$ over $K$.






              share|cite|improve this answer









              $endgroup$


















                1












                $begingroup$

                Let's say the dimension of $F$ as a vector space over $K$ is $n$. This means there is a basis of $F$ with a cardinality of $n$ elements. We will call this basis $f_1, f_2, ..., f_n$. By the definition of a basis, every element of $F$ can be expressed in the form of $k_1f_1+k_2f_2+...+k_nf_n$ for some $k_1,k_2,...,k_n in K$.



                Now, since $K$ has $49$ elements, there are $49$ possible values of $k_i$ for any $1leq i leq n$. Thus, there are $49$ choices for each $k_i$ and $n$ different $k_i$ variables, meaning there are $49^n$ possible values of $k_1f_1+k_2f_2+...+k_nf_n$. Thus, there are $49^n$ elements in the field $F$.



                Now, there are $7^6$ elements in the field $F$. Thus, we have the following equation:



                $$49^n=7^6rightarrow (7^2)^n=7^6rightarrow 7^{2n}=7^6rightarrow 2n=6rightarrow n=3$$



                Therefore, $F$ is a vector space of dimension $3$ over $K$.






                share|cite|improve this answer









                $endgroup$
















                  1












                  1








                  1





                  $begingroup$

                  Let's say the dimension of $F$ as a vector space over $K$ is $n$. This means there is a basis of $F$ with a cardinality of $n$ elements. We will call this basis $f_1, f_2, ..., f_n$. By the definition of a basis, every element of $F$ can be expressed in the form of $k_1f_1+k_2f_2+...+k_nf_n$ for some $k_1,k_2,...,k_n in K$.



                  Now, since $K$ has $49$ elements, there are $49$ possible values of $k_i$ for any $1leq i leq n$. Thus, there are $49$ choices for each $k_i$ and $n$ different $k_i$ variables, meaning there are $49^n$ possible values of $k_1f_1+k_2f_2+...+k_nf_n$. Thus, there are $49^n$ elements in the field $F$.



                  Now, there are $7^6$ elements in the field $F$. Thus, we have the following equation:



                  $$49^n=7^6rightarrow (7^2)^n=7^6rightarrow 7^{2n}=7^6rightarrow 2n=6rightarrow n=3$$



                  Therefore, $F$ is a vector space of dimension $3$ over $K$.






                  share|cite|improve this answer









                  $endgroup$



                  Let's say the dimension of $F$ as a vector space over $K$ is $n$. This means there is a basis of $F$ with a cardinality of $n$ elements. We will call this basis $f_1, f_2, ..., f_n$. By the definition of a basis, every element of $F$ can be expressed in the form of $k_1f_1+k_2f_2+...+k_nf_n$ for some $k_1,k_2,...,k_n in K$.



                  Now, since $K$ has $49$ elements, there are $49$ possible values of $k_i$ for any $1leq i leq n$. Thus, there are $49$ choices for each $k_i$ and $n$ different $k_i$ variables, meaning there are $49^n$ possible values of $k_1f_1+k_2f_2+...+k_nf_n$. Thus, there are $49^n$ elements in the field $F$.



                  Now, there are $7^6$ elements in the field $F$. Thus, we have the following equation:



                  $$49^n=7^6rightarrow (7^2)^n=7^6rightarrow 7^{2n}=7^6rightarrow 2n=6rightarrow n=3$$



                  Therefore, $F$ is a vector space of dimension $3$ over $K$.







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                  answered Jan 5 at 0:19









                  Noble MushtakNoble Mushtak

                  15.3k1835




                  15.3k1835























                      1












                      $begingroup$

                      Very simply, we have this formula, considering the prime subfield of $F$:
                      $$underbrace{[F:mathbf F_7]}_{=,6}=[F:L]cdotunderbrace{[L:mathbf F_7]}_{=,2}$$






                      share|cite|improve this answer









                      $endgroup$


















                        1












                        $begingroup$

                        Very simply, we have this formula, considering the prime subfield of $F$:
                        $$underbrace{[F:mathbf F_7]}_{=,6}=[F:L]cdotunderbrace{[L:mathbf F_7]}_{=,2}$$






                        share|cite|improve this answer









                        $endgroup$
















                          1












                          1








                          1





                          $begingroup$

                          Very simply, we have this formula, considering the prime subfield of $F$:
                          $$underbrace{[F:mathbf F_7]}_{=,6}=[F:L]cdotunderbrace{[L:mathbf F_7]}_{=,2}$$






                          share|cite|improve this answer









                          $endgroup$



                          Very simply, we have this formula, considering the prime subfield of $F$:
                          $$underbrace{[F:mathbf F_7]}_{=,6}=[F:L]cdotunderbrace{[L:mathbf F_7]}_{=,2}$$







                          share|cite|improve this answer












                          share|cite|improve this answer



                          share|cite|improve this answer










                          answered Jan 5 at 0:31









                          BernardBernard

                          124k741116




                          124k741116






























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