Determine matrix A with respect to standard basis $f:U->R^2$












0












$begingroup$


I am having trouble understanding my problem and what to calculate



I have been given the subspace
$U={x=$$
begin{vmatrix}
x_1\
x_2\
x_3\
end{vmatrix}
in F^3 | x_1 + x_2 + x_3 = 0} subset F^3
$



and the linear transformation $f: U rightarrow F^2 $
$fbegin{vmatrix}
x_1\
x_2\
x_3\
end{vmatrix}
=begin{vmatrix}
x_1\
x_2+x_3\
end{vmatrix}$



The question is to determine a matrix A that represent $f: U rightarrow F^2 $ with respect to the basis for U and standard basis $(e_1,e_2)$ for $F^2$



My attempt:
I have calculated the basis $B={begin{vmatrix}
1\
0\
-1\
end{vmatrix},begin{vmatrix}
0\
1\
-1\
end{vmatrix}}$



And my matrix A calculated from the linear transformation



$begin{vmatrix}
1&0&0\
0&1&1\
end{vmatrix}$



I'm aware the standard basis are $e_1=begin{vmatrix}
1\
0\
end{vmatrix} ,
e_2=begin{vmatrix}
0\
1\
end{vmatrix}$



I'm not sure about the next step. Do I calculate:
$fbegin{vmatrix}
1\
0\
-1\
end{vmatrix}
=begin{vmatrix}
1\
-1\
end{vmatrix}$



and do the same thing for the other basis or am I suppose to find a matrix A that's going to give me
$fbegin{vmatrix}
1\
0\
-1\
end{vmatrix}
=begin{vmatrix}
1\
0\
end{vmatrix}$



and



$fbegin{vmatrix}
0\
1\
-1\
end{vmatrix}
=begin{vmatrix}
0\
1\
end{vmatrix}$



I just don't understand the question. How am I suppose to find a matrix A with respect to the basis of U and the standard basis for $F^2$?










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    I am having trouble understanding my problem and what to calculate



    I have been given the subspace
    $U={x=$$
    begin{vmatrix}
    x_1\
    x_2\
    x_3\
    end{vmatrix}
    in F^3 | x_1 + x_2 + x_3 = 0} subset F^3
    $



    and the linear transformation $f: U rightarrow F^2 $
    $fbegin{vmatrix}
    x_1\
    x_2\
    x_3\
    end{vmatrix}
    =begin{vmatrix}
    x_1\
    x_2+x_3\
    end{vmatrix}$



    The question is to determine a matrix A that represent $f: U rightarrow F^2 $ with respect to the basis for U and standard basis $(e_1,e_2)$ for $F^2$



    My attempt:
    I have calculated the basis $B={begin{vmatrix}
    1\
    0\
    -1\
    end{vmatrix},begin{vmatrix}
    0\
    1\
    -1\
    end{vmatrix}}$



    And my matrix A calculated from the linear transformation



    $begin{vmatrix}
    1&0&0\
    0&1&1\
    end{vmatrix}$



    I'm aware the standard basis are $e_1=begin{vmatrix}
    1\
    0\
    end{vmatrix} ,
    e_2=begin{vmatrix}
    0\
    1\
    end{vmatrix}$



    I'm not sure about the next step. Do I calculate:
    $fbegin{vmatrix}
    1\
    0\
    -1\
    end{vmatrix}
    =begin{vmatrix}
    1\
    -1\
    end{vmatrix}$



    and do the same thing for the other basis or am I suppose to find a matrix A that's going to give me
    $fbegin{vmatrix}
    1\
    0\
    -1\
    end{vmatrix}
    =begin{vmatrix}
    1\
    0\
    end{vmatrix}$



    and



    $fbegin{vmatrix}
    0\
    1\
    -1\
    end{vmatrix}
    =begin{vmatrix}
    0\
    1\
    end{vmatrix}$



    I just don't understand the question. How am I suppose to find a matrix A with respect to the basis of U and the standard basis for $F^2$?










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      I am having trouble understanding my problem and what to calculate



      I have been given the subspace
      $U={x=$$
      begin{vmatrix}
      x_1\
      x_2\
      x_3\
      end{vmatrix}
      in F^3 | x_1 + x_2 + x_3 = 0} subset F^3
      $



      and the linear transformation $f: U rightarrow F^2 $
      $fbegin{vmatrix}
      x_1\
      x_2\
      x_3\
      end{vmatrix}
      =begin{vmatrix}
      x_1\
      x_2+x_3\
      end{vmatrix}$



      The question is to determine a matrix A that represent $f: U rightarrow F^2 $ with respect to the basis for U and standard basis $(e_1,e_2)$ for $F^2$



      My attempt:
      I have calculated the basis $B={begin{vmatrix}
      1\
      0\
      -1\
      end{vmatrix},begin{vmatrix}
      0\
      1\
      -1\
      end{vmatrix}}$



      And my matrix A calculated from the linear transformation



      $begin{vmatrix}
      1&0&0\
      0&1&1\
      end{vmatrix}$



      I'm aware the standard basis are $e_1=begin{vmatrix}
      1\
      0\
      end{vmatrix} ,
      e_2=begin{vmatrix}
      0\
      1\
      end{vmatrix}$



      I'm not sure about the next step. Do I calculate:
      $fbegin{vmatrix}
      1\
      0\
      -1\
      end{vmatrix}
      =begin{vmatrix}
      1\
      -1\
      end{vmatrix}$



      and do the same thing for the other basis or am I suppose to find a matrix A that's going to give me
      $fbegin{vmatrix}
      1\
      0\
      -1\
      end{vmatrix}
      =begin{vmatrix}
      1\
      0\
      end{vmatrix}$



      and



      $fbegin{vmatrix}
      0\
      1\
      -1\
      end{vmatrix}
      =begin{vmatrix}
      0\
      1\
      end{vmatrix}$



      I just don't understand the question. How am I suppose to find a matrix A with respect to the basis of U and the standard basis for $F^2$?










      share|cite|improve this question











      $endgroup$




      I am having trouble understanding my problem and what to calculate



      I have been given the subspace
      $U={x=$$
      begin{vmatrix}
      x_1\
      x_2\
      x_3\
      end{vmatrix}
      in F^3 | x_1 + x_2 + x_3 = 0} subset F^3
      $



      and the linear transformation $f: U rightarrow F^2 $
      $fbegin{vmatrix}
      x_1\
      x_2\
      x_3\
      end{vmatrix}
      =begin{vmatrix}
      x_1\
      x_2+x_3\
      end{vmatrix}$



      The question is to determine a matrix A that represent $f: U rightarrow F^2 $ with respect to the basis for U and standard basis $(e_1,e_2)$ for $F^2$



      My attempt:
      I have calculated the basis $B={begin{vmatrix}
      1\
      0\
      -1\
      end{vmatrix},begin{vmatrix}
      0\
      1\
      -1\
      end{vmatrix}}$



      And my matrix A calculated from the linear transformation



      $begin{vmatrix}
      1&0&0\
      0&1&1\
      end{vmatrix}$



      I'm aware the standard basis are $e_1=begin{vmatrix}
      1\
      0\
      end{vmatrix} ,
      e_2=begin{vmatrix}
      0\
      1\
      end{vmatrix}$



      I'm not sure about the next step. Do I calculate:
      $fbegin{vmatrix}
      1\
      0\
      -1\
      end{vmatrix}
      =begin{vmatrix}
      1\
      -1\
      end{vmatrix}$



      and do the same thing for the other basis or am I suppose to find a matrix A that's going to give me
      $fbegin{vmatrix}
      1\
      0\
      -1\
      end{vmatrix}
      =begin{vmatrix}
      1\
      0\
      end{vmatrix}$



      and



      $fbegin{vmatrix}
      0\
      1\
      -1\
      end{vmatrix}
      =begin{vmatrix}
      0\
      1\
      end{vmatrix}$



      I just don't understand the question. How am I suppose to find a matrix A with respect to the basis of U and the standard basis for $F^2$?







      linear-transformations






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 2 at 23:07







      mahma

















      asked Jan 2 at 22:39









      mahmamahma

      11




      11






















          1 Answer
          1






          active

          oldest

          votes


















          0












          $begingroup$

          The image of the first vector in the basis is
          $$
          begin{bmatrix} 1 \ 0+(-1) end{bmatrix}
          $$

          and the image of the second vector is
          $$
          begin{bmatrix} 0 \ 1+(-1) end{bmatrix}
          $$

          so the matrix is
          $$
          begin{bmatrix}
          1 & 0 \
          -1 & 0
          end{bmatrix}
          $$

          Note that the map $f$ can be more easily described as
          $$
          fbegin{bmatrix} x_1 \ x_2 \ x_3 end{bmatrix} = begin{bmatrix} x_1 \ -x_1 end{bmatrix}
          $$






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thats it? I'm afraid I don't fully understand how this is a representation of the standard basis despite it being simple and straightforward. So that means the matrix you have written is the representing matrix and the answer to the problem and not my matrix A calculated from the linear transformation?
            $endgroup$
            – mahma
            Jan 3 at 0:08










          • $begingroup$
            @mahma The map is $fcolon Uto F^2$ and the domain has dimension $2$, as well as the codomain; so the representing matrix must be $2times2$.
            $endgroup$
            – egreg
            Jan 3 at 0:47











          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%2f3060058%2fdetermine-matrix-a-with-respect-to-standard-basis-fu-r2%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









          0












          $begingroup$

          The image of the first vector in the basis is
          $$
          begin{bmatrix} 1 \ 0+(-1) end{bmatrix}
          $$

          and the image of the second vector is
          $$
          begin{bmatrix} 0 \ 1+(-1) end{bmatrix}
          $$

          so the matrix is
          $$
          begin{bmatrix}
          1 & 0 \
          -1 & 0
          end{bmatrix}
          $$

          Note that the map $f$ can be more easily described as
          $$
          fbegin{bmatrix} x_1 \ x_2 \ x_3 end{bmatrix} = begin{bmatrix} x_1 \ -x_1 end{bmatrix}
          $$






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thats it? I'm afraid I don't fully understand how this is a representation of the standard basis despite it being simple and straightforward. So that means the matrix you have written is the representing matrix and the answer to the problem and not my matrix A calculated from the linear transformation?
            $endgroup$
            – mahma
            Jan 3 at 0:08










          • $begingroup$
            @mahma The map is $fcolon Uto F^2$ and the domain has dimension $2$, as well as the codomain; so the representing matrix must be $2times2$.
            $endgroup$
            – egreg
            Jan 3 at 0:47
















          0












          $begingroup$

          The image of the first vector in the basis is
          $$
          begin{bmatrix} 1 \ 0+(-1) end{bmatrix}
          $$

          and the image of the second vector is
          $$
          begin{bmatrix} 0 \ 1+(-1) end{bmatrix}
          $$

          so the matrix is
          $$
          begin{bmatrix}
          1 & 0 \
          -1 & 0
          end{bmatrix}
          $$

          Note that the map $f$ can be more easily described as
          $$
          fbegin{bmatrix} x_1 \ x_2 \ x_3 end{bmatrix} = begin{bmatrix} x_1 \ -x_1 end{bmatrix}
          $$






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thats it? I'm afraid I don't fully understand how this is a representation of the standard basis despite it being simple and straightforward. So that means the matrix you have written is the representing matrix and the answer to the problem and not my matrix A calculated from the linear transformation?
            $endgroup$
            – mahma
            Jan 3 at 0:08










          • $begingroup$
            @mahma The map is $fcolon Uto F^2$ and the domain has dimension $2$, as well as the codomain; so the representing matrix must be $2times2$.
            $endgroup$
            – egreg
            Jan 3 at 0:47














          0












          0








          0





          $begingroup$

          The image of the first vector in the basis is
          $$
          begin{bmatrix} 1 \ 0+(-1) end{bmatrix}
          $$

          and the image of the second vector is
          $$
          begin{bmatrix} 0 \ 1+(-1) end{bmatrix}
          $$

          so the matrix is
          $$
          begin{bmatrix}
          1 & 0 \
          -1 & 0
          end{bmatrix}
          $$

          Note that the map $f$ can be more easily described as
          $$
          fbegin{bmatrix} x_1 \ x_2 \ x_3 end{bmatrix} = begin{bmatrix} x_1 \ -x_1 end{bmatrix}
          $$






          share|cite|improve this answer









          $endgroup$



          The image of the first vector in the basis is
          $$
          begin{bmatrix} 1 \ 0+(-1) end{bmatrix}
          $$

          and the image of the second vector is
          $$
          begin{bmatrix} 0 \ 1+(-1) end{bmatrix}
          $$

          so the matrix is
          $$
          begin{bmatrix}
          1 & 0 \
          -1 & 0
          end{bmatrix}
          $$

          Note that the map $f$ can be more easily described as
          $$
          fbegin{bmatrix} x_1 \ x_2 \ x_3 end{bmatrix} = begin{bmatrix} x_1 \ -x_1 end{bmatrix}
          $$







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Jan 2 at 23:57









          egregegreg

          180k1485202




          180k1485202












          • $begingroup$
            Thats it? I'm afraid I don't fully understand how this is a representation of the standard basis despite it being simple and straightforward. So that means the matrix you have written is the representing matrix and the answer to the problem and not my matrix A calculated from the linear transformation?
            $endgroup$
            – mahma
            Jan 3 at 0:08










          • $begingroup$
            @mahma The map is $fcolon Uto F^2$ and the domain has dimension $2$, as well as the codomain; so the representing matrix must be $2times2$.
            $endgroup$
            – egreg
            Jan 3 at 0:47


















          • $begingroup$
            Thats it? I'm afraid I don't fully understand how this is a representation of the standard basis despite it being simple and straightforward. So that means the matrix you have written is the representing matrix and the answer to the problem and not my matrix A calculated from the linear transformation?
            $endgroup$
            – mahma
            Jan 3 at 0:08










          • $begingroup$
            @mahma The map is $fcolon Uto F^2$ and the domain has dimension $2$, as well as the codomain; so the representing matrix must be $2times2$.
            $endgroup$
            – egreg
            Jan 3 at 0:47
















          $begingroup$
          Thats it? I'm afraid I don't fully understand how this is a representation of the standard basis despite it being simple and straightforward. So that means the matrix you have written is the representing matrix and the answer to the problem and not my matrix A calculated from the linear transformation?
          $endgroup$
          – mahma
          Jan 3 at 0:08




          $begingroup$
          Thats it? I'm afraid I don't fully understand how this is a representation of the standard basis despite it being simple and straightforward. So that means the matrix you have written is the representing matrix and the answer to the problem and not my matrix A calculated from the linear transformation?
          $endgroup$
          – mahma
          Jan 3 at 0:08












          $begingroup$
          @mahma The map is $fcolon Uto F^2$ and the domain has dimension $2$, as well as the codomain; so the representing matrix must be $2times2$.
          $endgroup$
          – egreg
          Jan 3 at 0:47




          $begingroup$
          @mahma The map is $fcolon Uto F^2$ and the domain has dimension $2$, as well as the codomain; so the representing matrix must be $2times2$.
          $endgroup$
          – egreg
          Jan 3 at 0:47


















          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%2f3060058%2fdetermine-matrix-a-with-respect-to-standard-basis-fu-r2%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

          android studio warns about leanback feature tag usage required on manifest while using Unity exported app?

          SQL update select statement

          'app-layout' is not a known element: how to share Component with different Modules