10.13 problem 1925

Internal problem ID [10248]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 9, system of higher order odes
Problem number: 1925.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\left (t \right )&=\operatorname {RootOf}\left (\textit {\_Z}^{3}+2 t \,\textit {\_Z}^{2}+\left (t^{2}-x \left (t \right )\right ) \textit {\_Z} +a y \left (t \right )-x \left (t \right ) t \right )\\ y^{\prime }\left (t \right )&=-\frac {t \operatorname {RootOf}\left (\textit {\_Z}^{3}+2 t \,\textit {\_Z}^{2}+\left (t^{2}-x \left (t \right )\right ) \textit {\_Z} +a y \left (t \right )-x \left (t \right ) t \right )}{a}-\frac {\operatorname {RootOf}\left (\textit {\_Z}^{3}+2 t \,\textit {\_Z}^{2}+\left (t^{2}-x \left (t \right )\right ) \textit {\_Z} +a y \left (t \right )-x \left (t \right ) t \right )^{2}}{a}+\frac {x \left (t \right )}{a} \end {align*}

Solution by Maple

Time used: 0.266 (sec). Leaf size: 220

dsolve([diff(x(t),t)^2+t*diff(x(t),t)+a*diff(y(t),t)-x(t)=0,diff(x(t),t)*diff(y(t),t)+t*diff(y(t),t)-y(t)=0],singsol=all)
 

\begin{align*} \left [\left \{x \left (t \right ) &= -\frac {t^{2}}{3}\right \}, \left \{y \left (t \right ) &= -\frac {t^{3}}{27 a}\right \}\right ] \\ \left [\{x \left (t \right ) &= c_{1} t +c_{2}\}, \left \{y \left (t \right ) &= \frac {-\left (\frac {d}{d t}x \left (t \right )\right )^{3}-2 \left (\frac {d}{d t}x \left (t \right )\right )^{2} t -t^{2} \left (\frac {d}{d t}x \left (t \right )\right )+x \left (t \right ) \left (\frac {d}{d t}x \left (t \right )\right )+x \left (t \right ) t}{a}\right \}\right ] \\ \left [\left \{x \left (t \right ) &= -\frac {5 t^{2}}{12}-\frac {t \left (-t -\sqrt {3}\, c_{1} \right )}{6}+\frac {c_{1}^{2}}{4}, x \left (t \right ) &= -\frac {5 t^{2}}{12}-\frac {t \left (-t +\sqrt {3}\, c_{1} \right )}{6}+\frac {c_{1}^{2}}{4}, x \left (t \right ) &= -\frac {5 t^{2}}{12}+\frac {t \left (t -\sqrt {3}\, c_{1} \right )}{6}+\frac {c_{1}^{2}}{4}, x \left (t \right ) &= -\frac {5 t^{2}}{12}+\frac {t \left (t +\sqrt {3}\, c_{1} \right )}{6}+\frac {c_{1}^{2}}{4}\right \}, \left \{y \left (t \right ) &= -\frac {-2 t^{2} \left (\frac {d}{d t}x \left (t \right )\right )-2 t^{3}-6 x \left (t \right ) \left (\frac {d}{d t}x \left (t \right )\right )-7 x \left (t \right ) t}{9 a}\right \}\right ] \\ \end{align*}

Solution by Mathematica

Time used: 0.015 (sec). Leaf size: 28

DSolve[{x'[t]^2+t*x'[t]+a*y'[t]-x[t]==0,x'[t]*y'[t]+t*y'[t]-y[t]==0},{x[t],y[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to a c_2+c_1 t+c_1{}^2 \\ y(t)\to c_2 (t+c_1) \\ \end{align*}