<item ident="X3-7273" title="X3 | Existence/uniqueness theorem for first-order IVPs | ver. 7273"> <itemmetadata> <qtimetadata> <qtimetadatafield> <fieldlabel>question_type</fieldlabel> <fieldentry>essay_question</fieldentry> </qtimetadatafield> </qtimetadata> </itemmetadata> <presentation> <material> <mattextxml> <div class="exercise-statement"> <p> <strong>X3.</strong> </p> <p> Explain what the Existence and Uniqueness Theorem for First Order IVPs guarantees about the existence and uniqueness of solutions for the following IVP. </p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?y'= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}} \hspace{2em} x( 4 )= 3" alt="y'= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}} \hspace{2em} x( 4 )= 3" title="y'= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}} \hspace{2em} x( 4 )= 3" data-latex="y'= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}} \hspace{2em} x( 4 )= 3"/> </p> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-statement"> <p> <strong>X3.</strong> </p> <p> Explain what the Existence and Uniqueness Theorem for First Order IVPs guarantees about the existence and uniqueness of solutions for the following IVP. </p> <p style="text-align:center;"> <img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?y'=%204%20%5C,%20%7B%5Cleft(2%20%5C,%20%7By%7D%20-%203%20%5C,%20t%20+%206%5Cright)%7D%5E%7B%5Cfrac%7B2%7D%7B3%7D%7D%20%5Chspace%7B2em%7D%20x(%204%20)=%203" alt="y'= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}} \hspace{2em} x( 4 )= 3" title="y'= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}} \hspace{2em} x( 4 )= 3" data-latex="y'= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}} \hspace{2em} x( 4 )= 3"> </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><img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?F(t,y)= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}}" alt="F(t,y)= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}}" title="F(t,y)= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}}" data-latex="F(t,y)= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}}"/> is continuous at and nearby the initial value so a solution exists for a nearby interval. </p> <p><img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?F_y= \frac{16}{3 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{1}{3}}}" alt="F_y= \frac{16}{3 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{1}{3}}}" title="F_y= \frac{16}{3 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{1}{3}}}" data-latex="F_y= \frac{16}{3 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{1}{3}}}"/> is not continous (or even defined) at the initial value so the guaranteed solution may not be unique. </p> </div> </mattextxml> <mattext texttype="text/html"><div class="exercise-answer"> <h4>Partial Answer:</h4> <p><img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?F(t,y)=%204%20%5C,%20%7B%5Cleft(2%20%5C,%20%7By%7D%20-%203%20%5C,%20t%20+%206%5Cright)%7D%5E%7B%5Cfrac%7B2%7D%7B3%7D%7D" alt="F(t,y)= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}}" title="F(t,y)= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}}" data-latex="F(t,y)= 4 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{2}{3}}"> is continuous at and nearby the initial value so a solution exists for a nearby interval. </p> <p><img style="border:1px #ddd solid;padding:5px;border-radius:5px;" src="https://latex.codecogs.com/svg.latex?F_y=%20%5Cfrac%7B16%7D%7B3%20%5C,%20%7B%5Cleft(2%20%5C,%20%7By%7D%20-%203%20%5C,%20t%20+%206%5Cright)%7D%5E%7B%5Cfrac%7B1%7D%7B3%7D%7D%7D" alt="F_y= \frac{16}{3 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{1}{3}}}" title="F_y= \frac{16}{3 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{1}{3}}}" data-latex="F_y= \frac{16}{3 \, {\left(2 \, {y} - 3 \, t + 6\right)}^{\frac{1}{3}}}"> is not continous (or even defined) at the initial value so the guaranteed solution may not be unique. </p> </div> </mattext> </material> </flow_mat> </itemfeedback> </item>