<item ident="M2-0011" title="M2 | Row operations as matrix multiplication | ver. 0011"> <itemmetadata> <qtimetadata> <qtimetadatafield> <fieldlabel>question_type</fieldlabel> <fieldentry>essay_question</fieldentry> </qtimetadatafield> </qtimetadata> </itemmetadata> <presentation> <material> <mattextxml> <div class="exercise-statement"> <p> <strong>M2.</strong> </p> <p>Let <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?A" alt="A" title="A" data-latex="A"/> be a <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?4 \times 4" alt="4 \times 4" title="4 \times 4" data-latex="4 \times 4"/> matrix.</p> <ol type="a"> <li>Give a <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?4 \times 4" alt="4 \times 4" title="4 \times 4" data-latex="4 \times 4"/> matrix <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?B" alt="B" title="B" data-latex="B"/> that may be used to perform the row operation <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_4 \to R_4 + 3R_2" alt="R_4 \to R_4 + 3R_2" title="R_4 \to R_4 + 3R_2" data-latex="R_4 \to R_4 + 3R_2"/>.</li> <li>Give a <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?4 \times 4" alt="4 \times 4" title="4 \times 4" data-latex="4 \times 4"/> matrix <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?Q" alt="Q" title="Q" data-latex="Q"/> that may be used to perform the row operation <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_2 \leftrightarrow R_1" alt="R_2 \leftrightarrow R_1" title="R_2 \leftrightarrow R_1" data-latex="R_2 \leftrightarrow R_1"/>.</li> <li>Use matrix multiplication to describe the matrix obtained by applying <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_2 \leftrightarrow R_1" alt="R_2 \leftrightarrow R_1" title="R_2 \leftrightarrow R_1" data-latex="R_2 \leftrightarrow R_1"/> and then <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_4 \to R_4 + 3R_2" alt="R_4 \to R_4 + 3R_2" title="R_4 \to R_4 + 3R_2" data-latex="R_4 \to R_4 + 3R_2"/> to <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?A" alt="A" title="A" data-latex="A"/> (note the order). </li> </ol> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-statement"> <p> <strong>M2.</strong> </p> <p>Let <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?A" alt="A" title="A" data-latex="A"> be a <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?4%20%5Ctimes%204" alt="4 \times 4" title="4 \times 4" data-latex="4 \times 4"> matrix.</p> <ol type="a"> <li>Give a <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?4%20%5Ctimes%204" alt="4 \times 4" title="4 \times 4" data-latex="4 \times 4"> matrix <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?B" alt="B" title="B" data-latex="B"> that may be used to perform the row operation <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_4%20%5Cto%20R_4%20+%203R_2" alt="R_4 \to R_4 + 3R_2" title="R_4 \to R_4 + 3R_2" data-latex="R_4 \to R_4 + 3R_2">.</li> <li>Give a <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?4%20%5Ctimes%204" alt="4 \times 4" title="4 \times 4" data-latex="4 \times 4"> matrix <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?Q" alt="Q" title="Q" data-latex="Q"> that may be used to perform the row operation <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_2%20%5Cleftrightarrow%20R_1" alt="R_2 \leftrightarrow R_1" title="R_2 \leftrightarrow R_1" data-latex="R_2 \leftrightarrow R_1">.</li> <li>Use matrix multiplication to describe the matrix obtained by applying <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_2%20%5Cleftrightarrow%20R_1" alt="R_2 \leftrightarrow R_1" title="R_2 \leftrightarrow R_1" data-latex="R_2 \leftrightarrow R_1"> and then <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_4%20%5Cto%20R_4%20+%203R_2" alt="R_4 \to R_4 + 3R_2" title="R_4 \to R_4 + 3R_2" data-latex="R_4 \to R_4 + 3R_2"> to <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?A" alt="A" title="A" data-latex="A"> (note the order). </li> </ol> </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> <ol type="a"> <li> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?B= \left[\begin{array}{cccc} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 3 & 0 & 1 \end{array}\right]" alt="B= \left[\begin{array}{cccc} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 3 & 0 & 1 \end{array}\right]" title="B= \left[\begin{array}{cccc} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 3 & 0 & 1 \end{array}\right]" data-latex="B= \left[\begin{array}{cccc} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 3 & 0 & 1 \end{array}\right]"/> </li> <li> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?Q= \left[\begin{array}{cccc} 0 & 1 & 0 & 0 \\ 1 & 0 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" alt="Q= \left[\begin{array}{cccc} 0 & 1 & 0 & 0 \\ 1 & 0 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" title="Q= \left[\begin{array}{cccc} 0 & 1 & 0 & 0 \\ 1 & 0 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" data-latex="Q= \left[\begin{array}{cccc} 0 & 1 & 0 & 0 \\ 1 & 0 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]"/> </li> <li> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?BQA" alt="BQA" title="BQA" data-latex="BQA"/> </li> </ol> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-answer"> <h4>Partial Answer:</h4> <ol type="a"> <li> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?B=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D%201%20&amp;%200%20&amp;%200%20&amp;%200%20%5C%5C%200%20&amp;%201%20&amp;%200%20&amp;%200%20%5C%5C%200%20&amp;%200%20&amp;%201%20&amp;%200%20%5C%5C%200%20&amp;%203%20&amp;%200%20&amp;%201%20%5Cend%7Barray%7D%5Cright%5D" alt="B= \left[\begin{array}{cccc} 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 3 &amp; 0 &amp; 1 \end{array}\right]" title="B= \left[\begin{array}{cccc} 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 3 &amp; 0 &amp; 1 \end{array}\right]" data-latex="B= \left[\begin{array}{cccc} 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 3 &amp; 0 &amp; 1 \end{array}\right]"> </li> <li> <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%200%20&amp;%201%20&amp;%200%20&amp;%200%20%5C%5C%201%20&amp;%200%20&amp;%200%20&amp;%200%20%5C%5C%200%20&amp;%200%20&amp;%201%20&amp;%200%20%5C%5C%200%20&amp;%200%20&amp;%200%20&amp;%201%20%5Cend%7Barray%7D%5Cright%5D" alt="Q= \left[\begin{array}{cccc} 0 &amp; 1 &amp; 0 &amp; 0 \\ 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]" title="Q= \left[\begin{array}{cccc} 0 &amp; 1 &amp; 0 &amp; 0 \\ 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]" data-latex="Q= \left[\begin{array}{cccc} 0 &amp; 1 &amp; 0 &amp; 0 \\ 1 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]"> </li> <li> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?BQA" alt="BQA" title="BQA" data-latex="BQA"> </li> </ol> </div> </mattext> </material> </flow_mat> </itemfeedback> </item>