11.1.8 problem 17

Internal problem ID [1469]
Book : Elementary differential equations and boundary value problems, 11th ed., Boyce, DiPrima, Meade
Section : Chapter 4.1, Higher order linear differential equations. General theory. page 173
Problem number : 17
Date solved : Tuesday, January 28, 2025 at 02:35:39 PM
CAS classification : [[_3rd_order, _with_linear_symmetries]]

\begin{align*} t y^{\prime \prime \prime }+2 y^{\prime \prime }-y^{\prime }+y t&=0 \end{align*}

Solution by Maple

Time used: 0.059 (sec). Leaf size: 144

dsolve(t*diff(y(t),t$3)+2*diff(y(t),t$2)-diff(y(t),t)+t*y(t)=0,y(t), singsol=all)
 
\[ y = {\mathrm e}^{-\frac {t \left (i \sqrt {3}-1\right )}{2}} \left (\operatorname {KummerM}\left (\frac {1}{2}-\frac {i \sqrt {3}}{6}, 1, i \sqrt {3}\, t \right ) \left (\int \operatorname {KummerU}\left (\frac {1}{2}-\frac {i \sqrt {3}}{6}, 1, i \sqrt {3}\, t \right ) {\mathrm e}^{-\frac {t \left (i \sqrt {3}+3\right )}{2}}d t \right ) c_3 -\operatorname {KummerU}\left (\frac {1}{2}-\frac {i \sqrt {3}}{6}, 1, i \sqrt {3}\, t \right ) \left (\int \operatorname {KummerM}\left (\frac {1}{2}-\frac {i \sqrt {3}}{6}, 1, i \sqrt {3}\, t \right ) {\mathrm e}^{-\frac {t \left (i \sqrt {3}+3\right )}{2}}d t \right ) c_3 +c_1 \operatorname {KummerM}\left (\frac {1}{2}-\frac {i \sqrt {3}}{6}, 1, i \sqrt {3}\, t \right )+c_2 \operatorname {KummerU}\left (\frac {1}{2}-\frac {i \sqrt {3}}{6}, 1, i \sqrt {3}\, t \right )\right ) \]

Solution by Mathematica

Time used: 0.660 (sec). Leaf size: 520

DSolve[t*D[ y[t],{t,3}]+2*D[y[t],{t,2}]-D[y[t],t]+t*y[t]==0,y[t],t,IncludeSingularSolutions -> True]
 
\[ y(t)\to e^{\frac {1}{2} \left (t-i \sqrt {3} t\right )} \left (c_3 \operatorname {HypergeometricU}\left (\frac {1}{6} \left (3-i \sqrt {3}\right ),1,i \sqrt {3} t\right ) \int _1^t\frac {2 e^{\frac {1}{2} i \left (3 i+\sqrt {3}\right ) K[1]} \operatorname {LaguerreL}\left (\frac {1}{6} i \left (3 i+\sqrt {3}\right ),i \sqrt {3} K[1]\right )}{\left (-1-i \sqrt {3}\right ) K[1] \left (\operatorname {Hypergeometric1F1}\left (\frac {1}{6} \left (9-i \sqrt {3}\right ),2,i \sqrt {3} K[1]\right ) \operatorname {HypergeometricU}\left (\frac {1}{6} \left (3-i \sqrt {3}\right ),1,i \sqrt {3} K[1]\right )+\operatorname {HypergeometricU}\left (\frac {1}{6} \left (9-i \sqrt {3}\right ),2,i \sqrt {3} K[1]\right ) \operatorname {LaguerreL}\left (\frac {1}{6} i \left (3 i+\sqrt {3}\right ),i \sqrt {3} K[1]\right )\right )}dK[1]+c_3 \operatorname {LaguerreL}\left (\frac {1}{6} i \left (3 i+\sqrt {3}\right ),i \sqrt {3} t\right ) \int _1^t-\frac {2 i e^{\frac {1}{2} i \left (3 i+\sqrt {3}\right ) K[2]} \operatorname {HypergeometricU}\left (\frac {1}{6} \left (3-i \sqrt {3}\right ),1,i \sqrt {3} K[2]\right )}{\left (-i+\sqrt {3}\right ) K[2] \left (\operatorname {Hypergeometric1F1}\left (\frac {1}{6} \left (9-i \sqrt {3}\right ),2,i \sqrt {3} K[2]\right ) \operatorname {HypergeometricU}\left (\frac {1}{6} \left (3-i \sqrt {3}\right ),1,i \sqrt {3} K[2]\right )+\operatorname {HypergeometricU}\left (\frac {1}{6} \left (9-i \sqrt {3}\right ),2,i \sqrt {3} K[2]\right ) \operatorname {LaguerreL}\left (\frac {1}{6} i \left (3 i+\sqrt {3}\right ),i \sqrt {3} K[2]\right )\right )}dK[2]+c_1 \operatorname {HypergeometricU}\left (\frac {1}{6} \left (3-i \sqrt {3}\right ),1,i \sqrt {3} t\right )+c_2 \operatorname {LaguerreL}\left (\frac {1}{6} i \left (3 i+\sqrt {3}\right ),i \sqrt {3} t\right )\right ) \]