4.21 problem 1469

Internal problem ID [9796]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 3, linear third order
Problem number: 1469.
ODE order: 3.
ODE degree: 1.

CAS Maple gives this as type [[_3rd_order, _with_linear_symmetries]]

\[ \boxed {y^{\prime \prime \prime }+3 a x y^{\prime \prime }+3 a^{2} x^{2} y^{\prime }+a^{3} x^{3} y=0} \]

Solution by Maple

Time used: 0.015 (sec). Leaf size: 46

dsolve(diff(diff(diff(y(x),x),x),x)+3*a*x*diff(diff(y(x),x),x)+3*a^2*x^2*diff(y(x),x)+a^3*x^3*y(x)=0,y(x), singsol=all)
 

\[ y \left (x \right ) = {\mathrm e}^{-\frac {x \left (2 \sqrt {3}\, \sqrt {a}+a x \right )}{2}} \left (c_{2} {\mathrm e}^{2 \sqrt {3}\, \sqrt {a}\, x}+c_{1} {\mathrm e}^{\sqrt {3}\, \sqrt {a}\, x}+c_{3} \right ) \]

Solution by Mathematica

Time used: 0.009 (sec). Leaf size: 68

DSolve[a^3*x^3*y[x] + 3*a^2*x^2*y'[x] + 3*a*x*y''[x] + Derivative[3][y][x] == 0,y[x],x,IncludeSingularSolutions -> True]
                                                                                    
                                                                                    
 

\[ y(x)\to e^{-\frac {a x^2}{2}-\sqrt {3} \sqrt {a} x} \left (c_1 e^{\sqrt {3} \sqrt {a} x}+c_3 e^{2 \sqrt {3} \sqrt {a} x}+c_2\right ) \]