<item ident="F4-5847" title="F4 | Implicit solutions for exact IVPs | ver. 5847"> <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?0 = -8 \, t^{2} y {y'} + 2 \, t^{2} {y'} + 3 \, y^{2} + 5 \, y" alt="0 = -8 \, t^{2} y {y'} + 2 \, t^{2} {y'} + 3 \, y^{2} + 5 \, y" title="0 = -8 \, t^{2} y {y'} + 2 \, t^{2} {y'} + 3 \, y^{2} + 5 \, y" data-latex="0 = -8 \, t^{2} y {y'} + 2 \, t^{2} {y'} + 3 \, y^{2} + 5 \, 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 y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" alt="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" title="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" data-latex="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y"/> </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?0%20=%20-8%20%5C,%20t%5E%7B2%7D%20y%20%7By'%7D%20+%202%20%5C,%20t%5E%7B2%7D%20%7By'%7D%20+%203%20%5C,%20y%5E%7B2%7D%20+%205%20%5C,%20y" alt="0 = -8 \, t^{2} y {y'} + 2 \, t^{2} {y'} + 3 \, y^{2} + 5 \, y" title="0 = -8 \, t^{2} y {y'} + 2 \, t^{2} {y'} + 3 \, y^{2} + 5 \, y" data-latex="0 = -8 \, t^{2} y {y'} + 2 \, t^{2} {y'} + 3 \, y^{2} + 5 \, 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%20y%20%7By'%7D%20+%203%20%5C,%20y%5E%7B2%7D%20=%20-2%20%5C,%20t%5E%7B2%7D%20%7By'%7D%20-%204%20%5C,%20t%20y%20-%205%20%5C,%20t%20%7By'%7D%20-%205%20%5C,%20y" alt="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" title="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" data-latex="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y"> </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(%201%20)=%20-1" 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?6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" alt="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" title="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" data-latex="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, 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?-2 \, t^{2} y - 3 \, t y^{2} - 5 \, t y = 4" alt="-2 \, t^{2} y - 3 \, t y^{2} - 5 \, t y = 4" title="-2 \, t^{2} y - 3 \, t y^{2} - 5 \, t y = 4" data-latex="-2 \, t^{2} y - 3 \, t y^{2} - 5 \, t y = 4"/> </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?6%20%5C,%20t%20y%20%7By'%7D%20+%203%20%5C,%20y%5E%7B2%7D%20=%20-2%20%5C,%20t%5E%7B2%7D%20%7By'%7D%20-%204%20%5C,%20t%20y%20-%205%20%5C,%20t%20%7By'%7D%20-%205%20%5C,%20y" alt="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" title="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, y" data-latex="6 \, t y {y'} + 3 \, y^{2} = -2 \, t^{2} {y'} - 4 \, t y - 5 \, t {y'} - 5 \, 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?-2%20%5C,%20t%5E%7B2%7D%20y%20-%203%20%5C,%20t%20y%5E%7B2%7D%20-%205%20%5C,%20t%20y%20=%204" alt="-2 \, t^{2} y - 3 \, t y^{2} - 5 \, t y = 4" title="-2 \, t^{2} y - 3 \, t y^{2} - 5 \, t y = 4" data-latex="-2 \, t^{2} y - 3 \, t y^{2} - 5 \, t y = 4"> </p> </div> </mattext> </material> </flow_mat> </itemfeedback> </item>