<item ident="F4-6005" title="F4 | Implicit solutions for exact IVPs | ver. 6005"> <itemmetadata> <qtimetadata> <qtimetadatafield> <fieldlabel>question_type</fieldlabel> <fieldentry>essay_question</fieldentry> </qtimetadatafield> </qtimetadata> </itemmetadata> <presentation> <material> <mattextxml> <div class="exercise-statement"> <p> <strong>F4.</strong> </p> <p> Determine which of the following ODEs is exact. </p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" alt="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" title="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" data-latex="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}"/> </p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?-6 \, t^{2} y {y'} + 6 \, t y - y = 6 \, y^{2} {y'} - 5 \, y^{2}" alt="-6 \, t^{2} y {y'} + 6 \, t y - y = 6 \, y^{2} {y'} - 5 \, y^{2}" title="-6 \, t^{2} y {y'} + 6 \, t y - y = 6 \, y^{2} {y'} - 5 \, y^{2}" data-latex="-6 \, t^{2} y {y'} + 6 \, t y - y = 6 \, y^{2} {y'} - 5 \, y^{2}"/> </p> <p> Then find an implicit solution for this exact ODE satisfying the initial value <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?y( -1 )= 1" alt="y( -1 )= 1" title="y( -1 )= 1" data-latex="y( -1 )= 1"/>. </p> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-statement"> <p> <strong>F4.</strong> </p> <p> Determine which of the following ODEs is exact. </p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?5%20%5C,%20y%5E%7B2%7D%20-%20t%20%7By'%7D%20-%20y%20=%20-10%20%5C,%20t%20y%20%7By'%7D%20+%206%20%5C,%20y%5E%7B2%7D%20%7By'%7D" alt="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" title="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" data-latex="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}"> </p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?-6%20%5C,%20t%5E%7B2%7D%20y%20%7By'%7D%20+%206%20%5C,%20t%20y%20-%20y%20=%206%20%5C,%20y%5E%7B2%7D%20%7By'%7D%20-%205%20%5C,%20y%5E%7B2%7D" alt="-6 \, t^{2} y {y'} + 6 \, t y - y = 6 \, y^{2} {y'} - 5 \, y^{2}" title="-6 \, t^{2} y {y'} + 6 \, t y - y = 6 \, y^{2} {y'} - 5 \, y^{2}" data-latex="-6 \, t^{2} y {y'} + 6 \, t y - y = 6 \, y^{2} {y'} - 5 \, y^{2}"> </p> <p> Then find an implicit solution for this exact ODE satisfying the initial value <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?y(%20-1%20)=%201" alt="y( -1 )= 1" title="y( -1 )= 1" data-latex="y( -1 )= 1">. </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>The following ODE is exact.</p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" alt="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" title="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" data-latex="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}"/> </p> <p> Its implicit solution satisfying the initial value is: </p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?-5 \, t y^{2} + 2 \, y^{3} + t y = 6" alt="-5 \, t y^{2} + 2 \, y^{3} + t y = 6" title="-5 \, t y^{2} + 2 \, y^{3} + t y = 6" data-latex="-5 \, t y^{2} + 2 \, y^{3} + t y = 6"/> </p> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-answer"> <h4>Partial Answer:</h4> <p>The following ODE is exact.</p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?5%20%5C,%20y%5E%7B2%7D%20-%20t%20%7By'%7D%20-%20y%20=%20-10%20%5C,%20t%20y%20%7By'%7D%20+%206%20%5C,%20y%5E%7B2%7D%20%7By'%7D" alt="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" title="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}" data-latex="5 \, y^{2} - t {y'} - y = -10 \, t y {y'} + 6 \, y^{2} {y'}"> </p> <p> Its implicit solution satisfying the initial value is: </p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?-5%20%5C,%20t%20y%5E%7B2%7D%20+%202%20%5C,%20y%5E%7B3%7D%20+%20t%20y%20=%206" alt="-5 \, t y^{2} + 2 \, y^{3} + t y = 6" title="-5 \, t y^{2} + 2 \, y^{3} + t y = 6" data-latex="-5 \, t y^{2} + 2 \, y^{3} + t y = 6"> </p> </div> </mattext> </material> </flow_mat> </itemfeedback> </item>