<item ident="M4-0008" title="M4 | Finding a matrix inverse | ver. 0008"> <itemmetadata> <qtimetadata> <qtimetadatafield> <fieldlabel>question_type</fieldlabel> <fieldentry>essay_question</fieldentry> </qtimetadatafield> </qtimetadata> </itemmetadata> <presentation> <material> <mattextxml> <div class="exercise-statement"> <p> <strong>M4.</strong> </p> <p>Show how to find the inverse of the matrix <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?Q= \left[\begin{array}{cccc} -2 & 5 & 1 & 8 \\ -1 & 2 & 6 & 5 \\ -2 & 1 & 1 & 7 \\ 1 & -2 & -1 & -4 \end{array}\right]" alt="Q= \left[\begin{array}{cccc} -2 & 5 & 1 & 8 \\ -1 & 2 & 6 & 5 \\ -2 & 1 & 1 & 7 \\ 1 & -2 & -1 & -4 \end{array}\right]" title="Q= \left[\begin{array}{cccc} -2 & 5 & 1 & 8 \\ -1 & 2 & 6 & 5 \\ -2 & 1 & 1 & 7 \\ 1 & -2 & -1 & -4 \end{array}\right]" data-latex="Q= \left[\begin{array}{cccc} -2 & 5 & 1 & 8 \\ -1 & 2 & 6 & 5 \\ -2 & 1 & 1 & 7 \\ 1 & -2 & -1 & -4 \end{array}\right]"/>.</p> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-statement"> <p> <strong>M4.</strong> </p> <p>Show how to find the inverse of the matrix <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?Q=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D%20-2%20&amp;%205%20&amp;%201%20&amp;%208%20%5C%5C%20-1%20&amp;%202%20&amp;%206%20&amp;%205%20%5C%5C%20-2%20&amp;%201%20&amp;%201%20&amp;%207%20%5C%5C%201%20&amp;%20-2%20&amp;%20-1%20&amp;%20-4%20%5Cend%7Barray%7D%5Cright%5D" alt="Q= \left[\begin{array}{cccc} -2 &amp; 5 &amp; 1 &amp; 8 \\ -1 &amp; 2 &amp; 6 &amp; 5 \\ -2 &amp; 1 &amp; 1 &amp; 7 \\ 1 &amp; -2 &amp; -1 &amp; -4 \end{array}\right]" title="Q= \left[\begin{array}{cccc} -2 &amp; 5 &amp; 1 &amp; 8 \\ -1 &amp; 2 &amp; 6 &amp; 5 \\ -2 &amp; 1 &amp; 1 &amp; 7 \\ 1 &amp; -2 &amp; -1 &amp; -4 \end{array}\right]" data-latex="Q= \left[\begin{array}{cccc} -2 &amp; 5 &amp; 1 &amp; 8 \\ -1 &amp; 2 &amp; 6 &amp; 5 \\ -2 &amp; 1 &amp; 1 &amp; 7 \\ 1 &amp; -2 &amp; -1 &amp; -4 \end{array}\right]">.</p> </div> </mattext> </material> <response_str ident="response1" rcardinality="Single"> <render_fib> <response_label ident="answer1" rshuffle="No"/> </render_fib> </response_str> </presentation> <itemfeedback ident="general_fb"> <flow_mat> <material> <mattextxml> <div class="exercise-answer"> <h4>Partial Answer:</h4> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?Q^{-1}= \left[\begin{array}{cccc} -49 & -13 & -17 & -144 \\ 4 & 1 & 1 & 11 \\ 3 & 1 & 1 & 9 \\ -15 & -4 & -5 & -44 \end{array}\right]" alt="Q^{-1}= \left[\begin{array}{cccc} -49 & -13 & -17 & -144 \\ 4 & 1 & 1 & 11 \\ 3 & 1 & 1 & 9 \\ -15 & -4 & -5 & -44 \end{array}\right]" title="Q^{-1}= \left[\begin{array}{cccc} -49 & -13 & -17 & -144 \\ 4 & 1 & 1 & 11 \\ 3 & 1 & 1 & 9 \\ -15 & -4 & -5 & -44 \end{array}\right]" data-latex="Q^{-1}= \left[\begin{array}{cccc} -49 & -13 & -17 & -144 \\ 4 & 1 & 1 & 11 \\ 3 & 1 & 1 & 9 \\ -15 & -4 & -5 & -44 \end{array}\right]"/> </p> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-answer"> <h4>Partial Answer:</h4> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?Q%5E%7B-1%7D=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D%20-49%20&amp;%20-13%20&amp;%20-17%20&amp;%20-144%20%5C%5C%204%20&amp;%201%20&amp;%201%20&amp;%2011%20%5C%5C%203%20&amp;%201%20&amp;%201%20&amp;%209%20%5C%5C%20-15%20&amp;%20-4%20&amp;%20-5%20&amp;%20-44%20%5Cend%7Barray%7D%5Cright%5D" alt="Q^{-1}= \left[\begin{array}{cccc} -49 &amp; -13 &amp; -17 &amp; -144 \\ 4 &amp; 1 &amp; 1 &amp; 11 \\ 3 &amp; 1 &amp; 1 &amp; 9 \\ -15 &amp; -4 &amp; -5 &amp; -44 \end{array}\right]" title="Q^{-1}= \left[\begin{array}{cccc} -49 &amp; -13 &amp; -17 &amp; -144 \\ 4 &amp; 1 &amp; 1 &amp; 11 \\ 3 &amp; 1 &amp; 1 &amp; 9 \\ -15 &amp; -4 &amp; -5 &amp; -44 \end{array}\right]" data-latex="Q^{-1}= \left[\begin{array}{cccc} -49 &amp; -13 &amp; -17 &amp; -144 \\ 4 &amp; 1 &amp; 1 &amp; 11 \\ 3 &amp; 1 &amp; 1 &amp; 9 \\ -15 &amp; -4 &amp; -5 &amp; -44 \end{array}\right]"> </p> </div> </mattext> </material> </flow_mat> </itemfeedback> </item>