<item ident="M4-0003" title="M4 | Finding a matrix inverse | ver. 0003"> <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?A= \left[\begin{array}{cccc} 1 & -1 & 0 & -1 \\ 0 & 1 & -2 & -5 \\ 0 & 0 & 1 & 5 \\ 0 & 0 & -1 & -4 \end{array}\right]" alt="A= \left[\begin{array}{cccc} 1 & -1 & 0 & -1 \\ 0 & 1 & -2 & -5 \\ 0 & 0 & 1 & 5 \\ 0 & 0 & -1 & -4 \end{array}\right]" title="A= \left[\begin{array}{cccc} 1 & -1 & 0 & -1 \\ 0 & 1 & -2 & -5 \\ 0 & 0 & 1 & 5 \\ 0 & 0 & -1 & -4 \end{array}\right]" data-latex="A= \left[\begin{array}{cccc} 1 & -1 & 0 & -1 \\ 0 & 1 & -2 & -5 \\ 0 & 0 & 1 & 5 \\ 0 & 0 & -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?A=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D%201%20&amp;%20-1%20&amp;%200%20&amp;%20-1%20%5C%5C%200%20&amp;%201%20&amp;%20-2%20&amp;%20-5%20%5C%5C%200%20&amp;%200%20&amp;%201%20&amp;%205%20%5C%5C%200%20&amp;%200%20&amp;%20-1%20&amp;%20-4%20%5Cend%7Barray%7D%5Cright%5D" alt="A= \left[\begin{array}{cccc} 1 &amp; -1 &amp; 0 &amp; -1 \\ 0 &amp; 1 &amp; -2 &amp; -5 \\ 0 &amp; 0 &amp; 1 &amp; 5 \\ 0 &amp; 0 &amp; -1 &amp; -4 \end{array}\right]" title="A= \left[\begin{array}{cccc} 1 &amp; -1 &amp; 0 &amp; -1 \\ 0 &amp; 1 &amp; -2 &amp; -5 \\ 0 &amp; 0 &amp; 1 &amp; 5 \\ 0 &amp; 0 &amp; -1 &amp; -4 \end{array}\right]" data-latex="A= \left[\begin{array}{cccc} 1 &amp; -1 &amp; 0 &amp; -1 \\ 0 &amp; 1 &amp; -2 &amp; -5 \\ 0 &amp; 0 &amp; 1 &amp; 5 \\ 0 &amp; 0 &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?A^{-1}= \left[\begin{array}{cccc} 1 & 1 & -2 & -4 \\ 0 & 1 & -3 & -5 \\ 0 & 0 & -4 & -5 \\ 0 & 0 & 1 & 1 \end{array}\right]" alt="A^{-1}= \left[\begin{array}{cccc} 1 & 1 & -2 & -4 \\ 0 & 1 & -3 & -5 \\ 0 & 0 & -4 & -5 \\ 0 & 0 & 1 & 1 \end{array}\right]" title="A^{-1}= \left[\begin{array}{cccc} 1 & 1 & -2 & -4 \\ 0 & 1 & -3 & -5 \\ 0 & 0 & -4 & -5 \\ 0 & 0 & 1 & 1 \end{array}\right]" data-latex="A^{-1}= \left[\begin{array}{cccc} 1 & 1 & -2 & -4 \\ 0 & 1 & -3 & -5 \\ 0 & 0 & -4 & -5 \\ 0 & 0 & 1 & 1 \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?A%5E%7B-1%7D=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D%201%20&amp;%201%20&amp;%20-2%20&amp;%20-4%20%5C%5C%200%20&amp;%201%20&amp;%20-3%20&amp;%20-5%20%5C%5C%200%20&amp;%200%20&amp;%20-4%20&amp;%20-5%20%5C%5C%200%20&amp;%200%20&amp;%201%20&amp;%201%20%5Cend%7Barray%7D%5Cright%5D" alt="A^{-1}= \left[\begin{array}{cccc} 1 &amp; 1 &amp; -2 &amp; -4 \\ 0 &amp; 1 &amp; -3 &amp; -5 \\ 0 &amp; 0 &amp; -4 &amp; -5 \\ 0 &amp; 0 &amp; 1 &amp; 1 \end{array}\right]" title="A^{-1}= \left[\begin{array}{cccc} 1 &amp; 1 &amp; -2 &amp; -4 \\ 0 &amp; 1 &amp; -3 &amp; -5 \\ 0 &amp; 0 &amp; -4 &amp; -5 \\ 0 &amp; 0 &amp; 1 &amp; 1 \end{array}\right]" data-latex="A^{-1}= \left[\begin{array}{cccc} 1 &amp; 1 &amp; -2 &amp; -4 \\ 0 &amp; 1 &amp; -3 &amp; -5 \\ 0 &amp; 0 &amp; -4 &amp; -5 \\ 0 &amp; 0 &amp; 1 &amp; 1 \end{array}\right]"> </p> </div> </mattext> </material> </flow_mat> </itemfeedback> </item>