<item ident="M2-0005" title="M2 | Row operations as matrix multiplication | ver. 0005"> <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?P" alt="P" title="P" data-latex="P"/> 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_1 \to 3R_1" alt="R_1 \to 3R_1" title="R_1 \to 3R_1" data-latex="R_1 \to 3R_1"/>.</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?N" alt="N" title="N" data-latex="N"/> 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_1 \to R_1 + 4R_3" alt="R_1 \to R_1 + 4R_3" title="R_1 \to R_1 + 4R_3" data-latex="R_1 \to R_1 + 4R_3"/>.</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_1 \to R_1 + 4R_3" alt="R_1 \to R_1 + 4R_3" title="R_1 \to R_1 + 4R_3" data-latex="R_1 \to R_1 + 4R_3"/> and then <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_1 \to 3R_1" alt="R_1 \to 3R_1" title="R_1 \to 3R_1" data-latex="R_1 \to 3R_1"/> 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?P" alt="P" title="P" data-latex="P"> 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_1%20%5Cto%203R_1" alt="R_1 \to 3R_1" title="R_1 \to 3R_1" data-latex="R_1 \to 3R_1">.</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?N" alt="N" title="N" data-latex="N"> 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_1%20%5Cto%20R_1%20+%204R_3" alt="R_1 \to R_1 + 4R_3" title="R_1 \to R_1 + 4R_3" data-latex="R_1 \to R_1 + 4R_3">.</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_1%20%5Cto%20R_1%20+%204R_3" alt="R_1 \to R_1 + 4R_3" title="R_1 \to R_1 + 4R_3" data-latex="R_1 \to R_1 + 4R_3"> and then <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?R_1%20%5Cto%203R_1" alt="R_1 \to 3R_1" title="R_1 \to 3R_1" data-latex="R_1 \to 3R_1"> 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?P= \left[\begin{array}{cccc} 3 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" alt="P= \left[\begin{array}{cccc} 3 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" title="P= \left[\begin{array}{cccc} 3 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" data-latex="P= \left[\begin{array}{cccc} 3 & 0 & 0 & 0 \\ 0 & 1 & 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?N= \left[\begin{array}{cccc} 1 & 0 & 4 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" alt="N= \left[\begin{array}{cccc} 1 & 0 & 4 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" title="N= \left[\begin{array}{cccc} 1 & 0 & 4 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]" data-latex="N= \left[\begin{array}{cccc} 1 & 0 & 4 & 0 \\ 0 & 1 & 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?PNA" alt="PNA" title="PNA" data-latex="PNA"/> </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?P=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D%203%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;%200%20&amp;%200%20&amp;%201%20%5Cend%7Barray%7D%5Cright%5D" alt="P= \left[\begin{array}{cccc} 3 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]" title="P= \left[\begin{array}{cccc} 3 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]" data-latex="P= \left[\begin{array}{cccc} 3 &amp; 0 &amp; 0 &amp; 0 \\ 0 &amp; 1 &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?N=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D%201%20&amp;%200%20&amp;%204%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;%200%20&amp;%200%20&amp;%201%20%5Cend%7Barray%7D%5Cright%5D" alt="N= \left[\begin{array}{cccc} 1 &amp; 0 &amp; 4 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]" title="N= \left[\begin{array}{cccc} 1 &amp; 0 &amp; 4 &amp; 0 \\ 0 &amp; 1 &amp; 0 &amp; 0 \\ 0 &amp; 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 0 &amp; 1 \end{array}\right]" data-latex="N= \left[\begin{array}{cccc} 1 &amp; 0 &amp; 4 &amp; 0 \\ 0 &amp; 1 &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?PNA" alt="PNA" title="PNA" data-latex="PNA"> </li> </ol> </div> </mattext> </material> </flow_mat> </itemfeedback> </item>