<item ident="F4-0493" title="F4 | Implicit solutions for exact IVPs | ver. 0493">
<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?-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" alt="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" title="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" data-latex="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t"/>
</p>
<p style="text-align:center;">
<img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?-4 \, t y^{2} + 3 \, y^{2} + 6 \, y {y'} - 4 \, y = 2 \, t^{2} {y'}" alt="-4 \, t y^{2} + 3 \, y^{2} + 6 \, y {y'} - 4 \, y = 2 \, t^{2} {y'}" title="-4 \, t y^{2} + 3 \, y^{2} + 6 \, y {y'} - 4 \, y = 2 \, t^{2} {y'}" data-latex="-4 \, t y^{2} + 3 \, y^{2} + 6 \, y {y'} - 4 \, y = 2 \, t^{2} {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?-4%20%5C,%20t%20%7By'%7D%20-%204%20%5C,%20y%20=%20-6%20%5C,%20t%20y%20%7By'%7D%20-%203%20%5C,%20y%5E%7B2%7D%20-%2010%20%5C,%20t" alt="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" title="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" data-latex="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t">
</p>
<p style="text-align:center;">
<img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?-4%20%5C,%20t%20y%5E%7B2%7D%20+%203%20%5C,%20y%5E%7B2%7D%20+%206%20%5C,%20y%20%7By'%7D%20-%204%20%5C,%20y%20=%202%20%5C,%20t%5E%7B2%7D%20%7By'%7D" alt="-4 \, t y^{2} + 3 \, y^{2} + 6 \, y {y'} - 4 \, y = 2 \, t^{2} {y'}" title="-4 \, t y^{2} + 3 \, y^{2} + 6 \, y {y'} - 4 \, y = 2 \, t^{2} {y'}" data-latex="-4 \, t y^{2} + 3 \, y^{2} + 6 \, y {y'} - 4 \, y = 2 \, t^{2} {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?-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" alt="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" title="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" data-latex="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t"/>
</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?3 \, t y^{2} + 5 \, t^{2} - 4 \, t y = 12" alt="3 \, t y^{2} + 5 \, t^{2} - 4 \, t y = 12" title="3 \, t y^{2} + 5 \, t^{2} - 4 \, t y = 12" data-latex="3 \, t y^{2} + 5 \, t^{2} - 4 \, t y = 12"/>
</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?-4%20%5C,%20t%20%7By'%7D%20-%204%20%5C,%20y%20=%20-6%20%5C,%20t%20y%20%7By'%7D%20-%203%20%5C,%20y%5E%7B2%7D%20-%2010%20%5C,%20t" alt="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" title="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t" data-latex="-4 \, t {y'} - 4 \, y = -6 \, t y {y'} - 3 \, y^{2} - 10 \, t">
</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?3%20%5C,%20t%20y%5E%7B2%7D%20+%205%20%5C,%20t%5E%7B2%7D%20-%204%20%5C,%20t%20y%20=%2012" alt="3 \, t y^{2} + 5 \, t^{2} - 4 \, t y = 12" title="3 \, t y^{2} + 5 \, t^{2} - 4 \, t y = 12" data-latex="3 \, t y^{2} + 5 \, t^{2} - 4 \, t y = 12">
</p>
</div>
</mattext>
</material>
</flow_mat>
</itemfeedback>
</item>