How to bring a Matrix to an advanced Coefficient matrix in row form?












0












$begingroup$


I just found this website on the Internet and you are really my last chance to help me with one task.
For $ a in mathbb{R}$, let the following linear equation system be given:
$$
begin{array}{rcrcrcc}
(a+1)x_{1} & + & (-a^2+6a-9)x_{2} & + & (a-2)x_{3} & = & 1\
(a+1)(a-3)x_{1} & + & (a^2-6a+9)x_{2} & + & 3x_{3} & = & a-3\
(a+1)x_{1} & + & (-a^2+6a-9)x_{2} & + & (a+1)x_{3} & = & 1\
end{array}
$$

Now I should bring that in the Matrix form $mathbf{A}x=b$, which isn't a problem.
$$
left(begin{array}{ccc}
(a+1) & (-a^2+6a-9) & (a-2) \
(a+1)(a-3) & (a^2-6a+9) & 3 \
(a+1) & (-a^2+6a-9) & (a+1)
end{array}right)
begin{pmatrix}
x_{1} \
x_{2} \
x_{3}
end{pmatrix}
=
begin{pmatrix}
1 \
a-3 \
1
end{pmatrix}
$$



But now I should bring it to the advanced Coefficient matrix in row form.
Can someone explain to me how to do it?
Thank you very much!










share|cite|improve this question











$endgroup$












  • $begingroup$
    Thank you, I saw that, i just need a hint how to bring it to the coefficient matrix
    $endgroup$
    – Alice
    Jan 31 at 8:36
















0












$begingroup$


I just found this website on the Internet and you are really my last chance to help me with one task.
For $ a in mathbb{R}$, let the following linear equation system be given:
$$
begin{array}{rcrcrcc}
(a+1)x_{1} & + & (-a^2+6a-9)x_{2} & + & (a-2)x_{3} & = & 1\
(a+1)(a-3)x_{1} & + & (a^2-6a+9)x_{2} & + & 3x_{3} & = & a-3\
(a+1)x_{1} & + & (-a^2+6a-9)x_{2} & + & (a+1)x_{3} & = & 1\
end{array}
$$

Now I should bring that in the Matrix form $mathbf{A}x=b$, which isn't a problem.
$$
left(begin{array}{ccc}
(a+1) & (-a^2+6a-9) & (a-2) \
(a+1)(a-3) & (a^2-6a+9) & 3 \
(a+1) & (-a^2+6a-9) & (a+1)
end{array}right)
begin{pmatrix}
x_{1} \
x_{2} \
x_{3}
end{pmatrix}
=
begin{pmatrix}
1 \
a-3 \
1
end{pmatrix}
$$



But now I should bring it to the advanced Coefficient matrix in row form.
Can someone explain to me how to do it?
Thank you very much!










share|cite|improve this question











$endgroup$












  • $begingroup$
    Thank you, I saw that, i just need a hint how to bring it to the coefficient matrix
    $endgroup$
    – Alice
    Jan 31 at 8:36














0












0








0





$begingroup$


I just found this website on the Internet and you are really my last chance to help me with one task.
For $ a in mathbb{R}$, let the following linear equation system be given:
$$
begin{array}{rcrcrcc}
(a+1)x_{1} & + & (-a^2+6a-9)x_{2} & + & (a-2)x_{3} & = & 1\
(a+1)(a-3)x_{1} & + & (a^2-6a+9)x_{2} & + & 3x_{3} & = & a-3\
(a+1)x_{1} & + & (-a^2+6a-9)x_{2} & + & (a+1)x_{3} & = & 1\
end{array}
$$

Now I should bring that in the Matrix form $mathbf{A}x=b$, which isn't a problem.
$$
left(begin{array}{ccc}
(a+1) & (-a^2+6a-9) & (a-2) \
(a+1)(a-3) & (a^2-6a+9) & 3 \
(a+1) & (-a^2+6a-9) & (a+1)
end{array}right)
begin{pmatrix}
x_{1} \
x_{2} \
x_{3}
end{pmatrix}
=
begin{pmatrix}
1 \
a-3 \
1
end{pmatrix}
$$



But now I should bring it to the advanced Coefficient matrix in row form.
Can someone explain to me how to do it?
Thank you very much!










share|cite|improve this question











$endgroup$




I just found this website on the Internet and you are really my last chance to help me with one task.
For $ a in mathbb{R}$, let the following linear equation system be given:
$$
begin{array}{rcrcrcc}
(a+1)x_{1} & + & (-a^2+6a-9)x_{2} & + & (a-2)x_{3} & = & 1\
(a+1)(a-3)x_{1} & + & (a^2-6a+9)x_{2} & + & 3x_{3} & = & a-3\
(a+1)x_{1} & + & (-a^2+6a-9)x_{2} & + & (a+1)x_{3} & = & 1\
end{array}
$$

Now I should bring that in the Matrix form $mathbf{A}x=b$, which isn't a problem.
$$
left(begin{array}{ccc}
(a+1) & (-a^2+6a-9) & (a-2) \
(a+1)(a-3) & (a^2-6a+9) & 3 \
(a+1) & (-a^2+6a-9) & (a+1)
end{array}right)
begin{pmatrix}
x_{1} \
x_{2} \
x_{3}
end{pmatrix}
=
begin{pmatrix}
1 \
a-3 \
1
end{pmatrix}
$$



But now I should bring it to the advanced Coefficient matrix in row form.
Can someone explain to me how to do it?
Thank you very much!







linear-algebra matrices






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 31 at 19:23









dantopa

6,65442245




6,65442245










asked Jan 30 at 20:14









AliceAlice

11




11












  • $begingroup$
    Thank you, I saw that, i just need a hint how to bring it to the coefficient matrix
    $endgroup$
    – Alice
    Jan 31 at 8:36


















  • $begingroup$
    Thank you, I saw that, i just need a hint how to bring it to the coefficient matrix
    $endgroup$
    – Alice
    Jan 31 at 8:36
















$begingroup$
Thank you, I saw that, i just need a hint how to bring it to the coefficient matrix
$endgroup$
– Alice
Jan 31 at 8:36




$begingroup$
Thank you, I saw that, i just need a hint how to bring it to the coefficient matrix
$endgroup$
– Alice
Jan 31 at 8:36










2 Answers
2






active

oldest

votes


















1












$begingroup$

This is a situation where Cramer's Rule applies quite nicely.



First, note that
$$
det(A)
= 3 , {left(a + 1right)} {left(a - 2right)} {left(a - 3right)}^{2}
$$

So, $A$ is invertible as long as $anotin{-1, 2, 3}$.



Next, define $A_i$ as the matrix obtained by replacing the $i$th column of $A$ with the vector $vec{b}=leftlangle1,,a - 3,,1rightrangle$. This gives
$$
begin{align*}
det(A_1) &= 3 , {left(a - 2right)} {left(a - 3right)}^{2} &
det(A_2) &= 0 &
det(A_3) &= 0
end{align*}
$$

By Cramer's Rule, we have
$$
begin{align*}
x_1 &= frac{det(A_1)}{det(A)} = frac{1}{a + 1} &
x_2 &= frac{det(A_2)}{det(A)} = 0 &
x_3 &= frac{det(A_3)}{det(A)} = 0
end{align*}
$$

Of course, we should also account for what happens if $ain{-1, 2, 3}$.



For $a=-1$, we can row-reduce the system to obtain
$$
operatorname{rref}left[begin{array}{rrr|r}
0 & -16 & -3 & 1 \
0 & 16 & 3 & -4 \
0 & -16 & 0 & 1
end{array}right]
=left[begin{array}{rrr|r}
0 & 1 & 0 & 0 \
0 & 0 & 1 & 0 \
0 & 0 & 0 & 1
end{array}right]
$$

For $a=2$, we have
$$
operatorname{rref}left[begin{array}{rrr|r}
3 & -1 & 0 & 1 \
-3 & 1 & 3 & -1 \
3 & -1 & 3 & 1
end{array}right]
=left[begin{array}{rrr|r}
1 & -frac{1}{3} & 0 & frac{1}{3} \
0 & 0 & 1 & 0 \
0 & 0 & 0 & 0
end{array}right]
$$

For $a=3$, we have
$$
operatorname{rref}left[begin{array}{rrr|r}
4 & 0 & 1 & 1 \
0 & 0 & 3 & 0 \
4 & 0 & 4 & 1
end{array}right]
=left[begin{array}{rrr|r}
1 & 0 & 0 & frac{1}{4} \
0 & 0 & 1 & 0 \
0 & 0 & 0 & 0
end{array}right]
$$






share|cite|improve this answer









$endgroup$





















    0












    $begingroup$

    Problem statement



    Solve the linear system $mathbf{A}x=b$:
    $$
    left[begin{array}{crc}
    a+1 & -(a-3)^2 & a-2 \
    (a-3) (a+1) & (a-3)^2 & 3 \
    a+1 & -(a-3)^2 & a+1
    end{array}right]
    left[begin{array}{c}
    x_{1} \ x_{2} \x_{3}
    end{array}right]
    =
    left[begin{array}{c}
    1 \ a-3 \ 1
    end{array}right].
    $$



    Gaussian Elimination



    Two reduction steps are used resulting in
    $$
    mathbf{E}_{2}mathbf{E}_{1}mathbf{A}x=mathbf{E}_{2}mathbf{E}_{1}b
    $$

    where
    $$
    mathbf{E}_{1} =
    left[
    begin{array}{ccc}
    frac{1}{a+1} & 0 & 0 \
    0 & frac{1}{a+1} & 0 \
    0 & 0 & frac{1}{a+1} \
    end{array}
    right], qquad
    mathbf{E}_{2} =
    left[
    begin{array}{rcc}
    1 & 0 & 0 \
    -1 & frac{1}{a-3} & 0 \
    -1 & 0 & 1 \
    end{array}
    right].
    $$



    Solution via back substitution



    The final linear system is
    $$
    left[
    begin{array}{ccc}
    1 & -frac{(a-3)^2}{a+1} &
    frac{a-2}{a+1} \
    0 & frac{a^2-5 a+6}{a+1} &
    frac{a^2-5 a+3}{-a^2+2 a+3} \
    0 & 0 & frac{3}{a+1} \
    end{array}
    right]
    left[begin{array}{c}
    x_{1} \ x_{2} \x_{3}
    end{array}right]
    =
    left[begin{array}{c}
    frac{1}{a+1} \ 0 \ 0
    end{array}right].
    $$

    Solution vis back substitution produces
    $$
    left[begin{array}{c}
    x_{1} \ x_{2} \ x_{3}
    end{array}right]
    =
    left[begin{array}{c}
    frac{1}{a+1} \ 0 \ 0
    end{array}right],
    qquad ane1.
    $$






    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%2f3094048%2fhow-to-bring-a-matrix-to-an-advanced-coefficient-matrix-in-row-form%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












      $begingroup$

      This is a situation where Cramer's Rule applies quite nicely.



      First, note that
      $$
      det(A)
      = 3 , {left(a + 1right)} {left(a - 2right)} {left(a - 3right)}^{2}
      $$

      So, $A$ is invertible as long as $anotin{-1, 2, 3}$.



      Next, define $A_i$ as the matrix obtained by replacing the $i$th column of $A$ with the vector $vec{b}=leftlangle1,,a - 3,,1rightrangle$. This gives
      $$
      begin{align*}
      det(A_1) &= 3 , {left(a - 2right)} {left(a - 3right)}^{2} &
      det(A_2) &= 0 &
      det(A_3) &= 0
      end{align*}
      $$

      By Cramer's Rule, we have
      $$
      begin{align*}
      x_1 &= frac{det(A_1)}{det(A)} = frac{1}{a + 1} &
      x_2 &= frac{det(A_2)}{det(A)} = 0 &
      x_3 &= frac{det(A_3)}{det(A)} = 0
      end{align*}
      $$

      Of course, we should also account for what happens if $ain{-1, 2, 3}$.



      For $a=-1$, we can row-reduce the system to obtain
      $$
      operatorname{rref}left[begin{array}{rrr|r}
      0 & -16 & -3 & 1 \
      0 & 16 & 3 & -4 \
      0 & -16 & 0 & 1
      end{array}right]
      =left[begin{array}{rrr|r}
      0 & 1 & 0 & 0 \
      0 & 0 & 1 & 0 \
      0 & 0 & 0 & 1
      end{array}right]
      $$

      For $a=2$, we have
      $$
      operatorname{rref}left[begin{array}{rrr|r}
      3 & -1 & 0 & 1 \
      -3 & 1 & 3 & -1 \
      3 & -1 & 3 & 1
      end{array}right]
      =left[begin{array}{rrr|r}
      1 & -frac{1}{3} & 0 & frac{1}{3} \
      0 & 0 & 1 & 0 \
      0 & 0 & 0 & 0
      end{array}right]
      $$

      For $a=3$, we have
      $$
      operatorname{rref}left[begin{array}{rrr|r}
      4 & 0 & 1 & 1 \
      0 & 0 & 3 & 0 \
      4 & 0 & 4 & 1
      end{array}right]
      =left[begin{array}{rrr|r}
      1 & 0 & 0 & frac{1}{4} \
      0 & 0 & 1 & 0 \
      0 & 0 & 0 & 0
      end{array}right]
      $$






      share|cite|improve this answer









      $endgroup$


















        1












        $begingroup$

        This is a situation where Cramer's Rule applies quite nicely.



        First, note that
        $$
        det(A)
        = 3 , {left(a + 1right)} {left(a - 2right)} {left(a - 3right)}^{2}
        $$

        So, $A$ is invertible as long as $anotin{-1, 2, 3}$.



        Next, define $A_i$ as the matrix obtained by replacing the $i$th column of $A$ with the vector $vec{b}=leftlangle1,,a - 3,,1rightrangle$. This gives
        $$
        begin{align*}
        det(A_1) &= 3 , {left(a - 2right)} {left(a - 3right)}^{2} &
        det(A_2) &= 0 &
        det(A_3) &= 0
        end{align*}
        $$

        By Cramer's Rule, we have
        $$
        begin{align*}
        x_1 &= frac{det(A_1)}{det(A)} = frac{1}{a + 1} &
        x_2 &= frac{det(A_2)}{det(A)} = 0 &
        x_3 &= frac{det(A_3)}{det(A)} = 0
        end{align*}
        $$

        Of course, we should also account for what happens if $ain{-1, 2, 3}$.



        For $a=-1$, we can row-reduce the system to obtain
        $$
        operatorname{rref}left[begin{array}{rrr|r}
        0 & -16 & -3 & 1 \
        0 & 16 & 3 & -4 \
        0 & -16 & 0 & 1
        end{array}right]
        =left[begin{array}{rrr|r}
        0 & 1 & 0 & 0 \
        0 & 0 & 1 & 0 \
        0 & 0 & 0 & 1
        end{array}right]
        $$

        For $a=2$, we have
        $$
        operatorname{rref}left[begin{array}{rrr|r}
        3 & -1 & 0 & 1 \
        -3 & 1 & 3 & -1 \
        3 & -1 & 3 & 1
        end{array}right]
        =left[begin{array}{rrr|r}
        1 & -frac{1}{3} & 0 & frac{1}{3} \
        0 & 0 & 1 & 0 \
        0 & 0 & 0 & 0
        end{array}right]
        $$

        For $a=3$, we have
        $$
        operatorname{rref}left[begin{array}{rrr|r}
        4 & 0 & 1 & 1 \
        0 & 0 & 3 & 0 \
        4 & 0 & 4 & 1
        end{array}right]
        =left[begin{array}{rrr|r}
        1 & 0 & 0 & frac{1}{4} \
        0 & 0 & 1 & 0 \
        0 & 0 & 0 & 0
        end{array}right]
        $$






        share|cite|improve this answer









        $endgroup$
















          1












          1








          1





          $begingroup$

          This is a situation where Cramer's Rule applies quite nicely.



          First, note that
          $$
          det(A)
          = 3 , {left(a + 1right)} {left(a - 2right)} {left(a - 3right)}^{2}
          $$

          So, $A$ is invertible as long as $anotin{-1, 2, 3}$.



          Next, define $A_i$ as the matrix obtained by replacing the $i$th column of $A$ with the vector $vec{b}=leftlangle1,,a - 3,,1rightrangle$. This gives
          $$
          begin{align*}
          det(A_1) &= 3 , {left(a - 2right)} {left(a - 3right)}^{2} &
          det(A_2) &= 0 &
          det(A_3) &= 0
          end{align*}
          $$

          By Cramer's Rule, we have
          $$
          begin{align*}
          x_1 &= frac{det(A_1)}{det(A)} = frac{1}{a + 1} &
          x_2 &= frac{det(A_2)}{det(A)} = 0 &
          x_3 &= frac{det(A_3)}{det(A)} = 0
          end{align*}
          $$

          Of course, we should also account for what happens if $ain{-1, 2, 3}$.



          For $a=-1$, we can row-reduce the system to obtain
          $$
          operatorname{rref}left[begin{array}{rrr|r}
          0 & -16 & -3 & 1 \
          0 & 16 & 3 & -4 \
          0 & -16 & 0 & 1
          end{array}right]
          =left[begin{array}{rrr|r}
          0 & 1 & 0 & 0 \
          0 & 0 & 1 & 0 \
          0 & 0 & 0 & 1
          end{array}right]
          $$

          For $a=2$, we have
          $$
          operatorname{rref}left[begin{array}{rrr|r}
          3 & -1 & 0 & 1 \
          -3 & 1 & 3 & -1 \
          3 & -1 & 3 & 1
          end{array}right]
          =left[begin{array}{rrr|r}
          1 & -frac{1}{3} & 0 & frac{1}{3} \
          0 & 0 & 1 & 0 \
          0 & 0 & 0 & 0
          end{array}right]
          $$

          For $a=3$, we have
          $$
          operatorname{rref}left[begin{array}{rrr|r}
          4 & 0 & 1 & 1 \
          0 & 0 & 3 & 0 \
          4 & 0 & 4 & 1
          end{array}right]
          =left[begin{array}{rrr|r}
          1 & 0 & 0 & frac{1}{4} \
          0 & 0 & 1 & 0 \
          0 & 0 & 0 & 0
          end{array}right]
          $$






          share|cite|improve this answer









          $endgroup$



          This is a situation where Cramer's Rule applies quite nicely.



          First, note that
          $$
          det(A)
          = 3 , {left(a + 1right)} {left(a - 2right)} {left(a - 3right)}^{2}
          $$

          So, $A$ is invertible as long as $anotin{-1, 2, 3}$.



          Next, define $A_i$ as the matrix obtained by replacing the $i$th column of $A$ with the vector $vec{b}=leftlangle1,,a - 3,,1rightrangle$. This gives
          $$
          begin{align*}
          det(A_1) &= 3 , {left(a - 2right)} {left(a - 3right)}^{2} &
          det(A_2) &= 0 &
          det(A_3) &= 0
          end{align*}
          $$

          By Cramer's Rule, we have
          $$
          begin{align*}
          x_1 &= frac{det(A_1)}{det(A)} = frac{1}{a + 1} &
          x_2 &= frac{det(A_2)}{det(A)} = 0 &
          x_3 &= frac{det(A_3)}{det(A)} = 0
          end{align*}
          $$

          Of course, we should also account for what happens if $ain{-1, 2, 3}$.



          For $a=-1$, we can row-reduce the system to obtain
          $$
          operatorname{rref}left[begin{array}{rrr|r}
          0 & -16 & -3 & 1 \
          0 & 16 & 3 & -4 \
          0 & -16 & 0 & 1
          end{array}right]
          =left[begin{array}{rrr|r}
          0 & 1 & 0 & 0 \
          0 & 0 & 1 & 0 \
          0 & 0 & 0 & 1
          end{array}right]
          $$

          For $a=2$, we have
          $$
          operatorname{rref}left[begin{array}{rrr|r}
          3 & -1 & 0 & 1 \
          -3 & 1 & 3 & -1 \
          3 & -1 & 3 & 1
          end{array}right]
          =left[begin{array}{rrr|r}
          1 & -frac{1}{3} & 0 & frac{1}{3} \
          0 & 0 & 1 & 0 \
          0 & 0 & 0 & 0
          end{array}right]
          $$

          For $a=3$, we have
          $$
          operatorname{rref}left[begin{array}{rrr|r}
          4 & 0 & 1 & 1 \
          0 & 0 & 3 & 0 \
          4 & 0 & 4 & 1
          end{array}right]
          =left[begin{array}{rrr|r}
          1 & 0 & 0 & frac{1}{4} \
          0 & 0 & 1 & 0 \
          0 & 0 & 0 & 0
          end{array}right]
          $$







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Jan 31 at 22:39









          Brian FitzpatrickBrian Fitzpatrick

          21.8k42959




          21.8k42959























              0












              $begingroup$

              Problem statement



              Solve the linear system $mathbf{A}x=b$:
              $$
              left[begin{array}{crc}
              a+1 & -(a-3)^2 & a-2 \
              (a-3) (a+1) & (a-3)^2 & 3 \
              a+1 & -(a-3)^2 & a+1
              end{array}right]
              left[begin{array}{c}
              x_{1} \ x_{2} \x_{3}
              end{array}right]
              =
              left[begin{array}{c}
              1 \ a-3 \ 1
              end{array}right].
              $$



              Gaussian Elimination



              Two reduction steps are used resulting in
              $$
              mathbf{E}_{2}mathbf{E}_{1}mathbf{A}x=mathbf{E}_{2}mathbf{E}_{1}b
              $$

              where
              $$
              mathbf{E}_{1} =
              left[
              begin{array}{ccc}
              frac{1}{a+1} & 0 & 0 \
              0 & frac{1}{a+1} & 0 \
              0 & 0 & frac{1}{a+1} \
              end{array}
              right], qquad
              mathbf{E}_{2} =
              left[
              begin{array}{rcc}
              1 & 0 & 0 \
              -1 & frac{1}{a-3} & 0 \
              -1 & 0 & 1 \
              end{array}
              right].
              $$



              Solution via back substitution



              The final linear system is
              $$
              left[
              begin{array}{ccc}
              1 & -frac{(a-3)^2}{a+1} &
              frac{a-2}{a+1} \
              0 & frac{a^2-5 a+6}{a+1} &
              frac{a^2-5 a+3}{-a^2+2 a+3} \
              0 & 0 & frac{3}{a+1} \
              end{array}
              right]
              left[begin{array}{c}
              x_{1} \ x_{2} \x_{3}
              end{array}right]
              =
              left[begin{array}{c}
              frac{1}{a+1} \ 0 \ 0
              end{array}right].
              $$

              Solution vis back substitution produces
              $$
              left[begin{array}{c}
              x_{1} \ x_{2} \ x_{3}
              end{array}right]
              =
              left[begin{array}{c}
              frac{1}{a+1} \ 0 \ 0
              end{array}right],
              qquad ane1.
              $$






              share|cite|improve this answer









              $endgroup$


















                0












                $begingroup$

                Problem statement



                Solve the linear system $mathbf{A}x=b$:
                $$
                left[begin{array}{crc}
                a+1 & -(a-3)^2 & a-2 \
                (a-3) (a+1) & (a-3)^2 & 3 \
                a+1 & -(a-3)^2 & a+1
                end{array}right]
                left[begin{array}{c}
                x_{1} \ x_{2} \x_{3}
                end{array}right]
                =
                left[begin{array}{c}
                1 \ a-3 \ 1
                end{array}right].
                $$



                Gaussian Elimination



                Two reduction steps are used resulting in
                $$
                mathbf{E}_{2}mathbf{E}_{1}mathbf{A}x=mathbf{E}_{2}mathbf{E}_{1}b
                $$

                where
                $$
                mathbf{E}_{1} =
                left[
                begin{array}{ccc}
                frac{1}{a+1} & 0 & 0 \
                0 & frac{1}{a+1} & 0 \
                0 & 0 & frac{1}{a+1} \
                end{array}
                right], qquad
                mathbf{E}_{2} =
                left[
                begin{array}{rcc}
                1 & 0 & 0 \
                -1 & frac{1}{a-3} & 0 \
                -1 & 0 & 1 \
                end{array}
                right].
                $$



                Solution via back substitution



                The final linear system is
                $$
                left[
                begin{array}{ccc}
                1 & -frac{(a-3)^2}{a+1} &
                frac{a-2}{a+1} \
                0 & frac{a^2-5 a+6}{a+1} &
                frac{a^2-5 a+3}{-a^2+2 a+3} \
                0 & 0 & frac{3}{a+1} \
                end{array}
                right]
                left[begin{array}{c}
                x_{1} \ x_{2} \x_{3}
                end{array}right]
                =
                left[begin{array}{c}
                frac{1}{a+1} \ 0 \ 0
                end{array}right].
                $$

                Solution vis back substitution produces
                $$
                left[begin{array}{c}
                x_{1} \ x_{2} \ x_{3}
                end{array}right]
                =
                left[begin{array}{c}
                frac{1}{a+1} \ 0 \ 0
                end{array}right],
                qquad ane1.
                $$






                share|cite|improve this answer









                $endgroup$
















                  0












                  0








                  0





                  $begingroup$

                  Problem statement



                  Solve the linear system $mathbf{A}x=b$:
                  $$
                  left[begin{array}{crc}
                  a+1 & -(a-3)^2 & a-2 \
                  (a-3) (a+1) & (a-3)^2 & 3 \
                  a+1 & -(a-3)^2 & a+1
                  end{array}right]
                  left[begin{array}{c}
                  x_{1} \ x_{2} \x_{3}
                  end{array}right]
                  =
                  left[begin{array}{c}
                  1 \ a-3 \ 1
                  end{array}right].
                  $$



                  Gaussian Elimination



                  Two reduction steps are used resulting in
                  $$
                  mathbf{E}_{2}mathbf{E}_{1}mathbf{A}x=mathbf{E}_{2}mathbf{E}_{1}b
                  $$

                  where
                  $$
                  mathbf{E}_{1} =
                  left[
                  begin{array}{ccc}
                  frac{1}{a+1} & 0 & 0 \
                  0 & frac{1}{a+1} & 0 \
                  0 & 0 & frac{1}{a+1} \
                  end{array}
                  right], qquad
                  mathbf{E}_{2} =
                  left[
                  begin{array}{rcc}
                  1 & 0 & 0 \
                  -1 & frac{1}{a-3} & 0 \
                  -1 & 0 & 1 \
                  end{array}
                  right].
                  $$



                  Solution via back substitution



                  The final linear system is
                  $$
                  left[
                  begin{array}{ccc}
                  1 & -frac{(a-3)^2}{a+1} &
                  frac{a-2}{a+1} \
                  0 & frac{a^2-5 a+6}{a+1} &
                  frac{a^2-5 a+3}{-a^2+2 a+3} \
                  0 & 0 & frac{3}{a+1} \
                  end{array}
                  right]
                  left[begin{array}{c}
                  x_{1} \ x_{2} \x_{3}
                  end{array}right]
                  =
                  left[begin{array}{c}
                  frac{1}{a+1} \ 0 \ 0
                  end{array}right].
                  $$

                  Solution vis back substitution produces
                  $$
                  left[begin{array}{c}
                  x_{1} \ x_{2} \ x_{3}
                  end{array}right]
                  =
                  left[begin{array}{c}
                  frac{1}{a+1} \ 0 \ 0
                  end{array}right],
                  qquad ane1.
                  $$






                  share|cite|improve this answer









                  $endgroup$



                  Problem statement



                  Solve the linear system $mathbf{A}x=b$:
                  $$
                  left[begin{array}{crc}
                  a+1 & -(a-3)^2 & a-2 \
                  (a-3) (a+1) & (a-3)^2 & 3 \
                  a+1 & -(a-3)^2 & a+1
                  end{array}right]
                  left[begin{array}{c}
                  x_{1} \ x_{2} \x_{3}
                  end{array}right]
                  =
                  left[begin{array}{c}
                  1 \ a-3 \ 1
                  end{array}right].
                  $$



                  Gaussian Elimination



                  Two reduction steps are used resulting in
                  $$
                  mathbf{E}_{2}mathbf{E}_{1}mathbf{A}x=mathbf{E}_{2}mathbf{E}_{1}b
                  $$

                  where
                  $$
                  mathbf{E}_{1} =
                  left[
                  begin{array}{ccc}
                  frac{1}{a+1} & 0 & 0 \
                  0 & frac{1}{a+1} & 0 \
                  0 & 0 & frac{1}{a+1} \
                  end{array}
                  right], qquad
                  mathbf{E}_{2} =
                  left[
                  begin{array}{rcc}
                  1 & 0 & 0 \
                  -1 & frac{1}{a-3} & 0 \
                  -1 & 0 & 1 \
                  end{array}
                  right].
                  $$



                  Solution via back substitution



                  The final linear system is
                  $$
                  left[
                  begin{array}{ccc}
                  1 & -frac{(a-3)^2}{a+1} &
                  frac{a-2}{a+1} \
                  0 & frac{a^2-5 a+6}{a+1} &
                  frac{a^2-5 a+3}{-a^2+2 a+3} \
                  0 & 0 & frac{3}{a+1} \
                  end{array}
                  right]
                  left[begin{array}{c}
                  x_{1} \ x_{2} \x_{3}
                  end{array}right]
                  =
                  left[begin{array}{c}
                  frac{1}{a+1} \ 0 \ 0
                  end{array}right].
                  $$

                  Solution vis back substitution produces
                  $$
                  left[begin{array}{c}
                  x_{1} \ x_{2} \ x_{3}
                  end{array}right]
                  =
                  left[begin{array}{c}
                  frac{1}{a+1} \ 0 \ 0
                  end{array}right],
                  qquad ane1.
                  $$







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered Jan 31 at 19:11









                  dantopadantopa

                  6,65442245




                  6,65442245






























                      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%2f3094048%2fhow-to-bring-a-matrix-to-an-advanced-coefficient-matrix-in-row-form%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

                      MongoDB - Not Authorized To Execute Command

                      in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith

                      How to fix TextFormField cause rebuild widget in Flutter