Find a Matrix A on the ring of integers modulo 3 so that KerA=ImB.











up vote
0
down vote

favorite












B={{1,1,1},{0,1,2},{2,1,0},{0,2,2}}



I understand that each vector from then span of column vectors of B is a solution for Ax=o and that matrix A should have four columns. However I don't know how many rows it should have and how to find it.










share|cite|improve this question


























    up vote
    0
    down vote

    favorite












    B={{1,1,1},{0,1,2},{2,1,0},{0,2,2}}



    I understand that each vector from then span of column vectors of B is a solution for Ax=o and that matrix A should have four columns. However I don't know how many rows it should have and how to find it.










    share|cite|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      B={{1,1,1},{0,1,2},{2,1,0},{0,2,2}}



      I understand that each vector from then span of column vectors of B is a solution for Ax=o and that matrix A should have four columns. However I don't know how many rows it should have and how to find it.










      share|cite|improve this question













      B={{1,1,1},{0,1,2},{2,1,0},{0,2,2}}



      I understand that each vector from then span of column vectors of B is a solution for Ax=o and that matrix A should have four columns. However I don't know how many rows it should have and how to find it.







      linear-algebra matrices modular-arithmetic






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 17 at 10:02









      Oleksandr

      362




      362






















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          1
          down vote













          Suppose $A$ has $r$ rows. As $mathbb Z_3$ is a field, by rank-nullity theorem,
          $$
          4 =text{dimension of domain of $A$}=operatorname{rank}(A)+operatorname{nullity}(A)=operatorname{rank}(A)+operatorname{rank}(B).
          $$

          Hence $r:=operatorname{rank}(A)=4-operatorname{rank}(B)$ and $A$ must have at least $r$ rows.






          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%2f3002156%2ffind-a-matrix-a-on-the-ring-of-integers-modulo-3-so-that-kera-imb%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
            1
            down vote













            Suppose $A$ has $r$ rows. As $mathbb Z_3$ is a field, by rank-nullity theorem,
            $$
            4 =text{dimension of domain of $A$}=operatorname{rank}(A)+operatorname{nullity}(A)=operatorname{rank}(A)+operatorname{rank}(B).
            $$

            Hence $r:=operatorname{rank}(A)=4-operatorname{rank}(B)$ and $A$ must have at least $r$ rows.






            share|cite|improve this answer

























              up vote
              1
              down vote













              Suppose $A$ has $r$ rows. As $mathbb Z_3$ is a field, by rank-nullity theorem,
              $$
              4 =text{dimension of domain of $A$}=operatorname{rank}(A)+operatorname{nullity}(A)=operatorname{rank}(A)+operatorname{rank}(B).
              $$

              Hence $r:=operatorname{rank}(A)=4-operatorname{rank}(B)$ and $A$ must have at least $r$ rows.






              share|cite|improve this answer























                up vote
                1
                down vote










                up vote
                1
                down vote









                Suppose $A$ has $r$ rows. As $mathbb Z_3$ is a field, by rank-nullity theorem,
                $$
                4 =text{dimension of domain of $A$}=operatorname{rank}(A)+operatorname{nullity}(A)=operatorname{rank}(A)+operatorname{rank}(B).
                $$

                Hence $r:=operatorname{rank}(A)=4-operatorname{rank}(B)$ and $A$ must have at least $r$ rows.






                share|cite|improve this answer












                Suppose $A$ has $r$ rows. As $mathbb Z_3$ is a field, by rank-nullity theorem,
                $$
                4 =text{dimension of domain of $A$}=operatorname{rank}(A)+operatorname{nullity}(A)=operatorname{rank}(A)+operatorname{rank}(B).
                $$

                Hence $r:=operatorname{rank}(A)=4-operatorname{rank}(B)$ and $A$ must have at least $r$ rows.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Nov 17 at 10:53









                user1551

                70.2k566125




                70.2k566125






























                     

                    draft saved


                    draft discarded



















































                     


                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3002156%2ffind-a-matrix-a-on-the-ring-of-integers-modulo-3-so-that-kera-imb%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

                    Bundesstraße 106

                    Verónica Boquete

                    Ida-Boy-Ed-Garten