Dimension of the field












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









$endgroup$

















    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









    $endgroup$















      1












      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






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Jan 5 at 0:12









      Gopi SGopi S

      285




      285






















          2 Answers
          2






          active

          oldest

          votes


















          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












            $begingroup$

            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









            $endgroup$














              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',
              autoActivateHeartbeat: false,
              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%2f3062266%2fdimension-of-the-field%23new-answer', 'question_page');
              }
              );

              Post as a guest















              Required, but never shown

























              2 Answers
              2






              active

              oldest

              votes








              2 Answers
              2






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes









              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












                $begingroup$

                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 $K$.







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  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






























                              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.




                              draft saved


                              draft discarded














                              StackExchange.ready(
                              function () {
                              StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3062266%2fdimension-of-the-field%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 do I know what Microsoft account the skydrive app is syncing to?

                              When does type information flow backwards in C++?

                              Grease: Live!