3.436 problem 1442

Internal problem ID [9770]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 2, linear second order
Problem number: 1442.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _with_linear_symmetries]]

\[ \boxed {y^{\prime \prime }+\frac {x y^{\prime }}{f \left (x \right )}-\frac {y}{f \left (x \right )}=0} \]

Solution by Maple

Time used: 0.047 (sec). Leaf size: 33

dsolve(diff(diff(y(x),x),x) = -x/f(x)*diff(y(x),x)+1/f(x)*y(x),y(x), singsol=all)
 

\[ y \left (x \right ) = x \left (\left (\int {\mathrm e}^{-\left (\int \frac {x^{2}+2 f \left (x \right )}{f \left (x \right ) x}d x \right )}d x \right ) c_{1} +c_{2} \right ) \]

Solution by Mathematica

Time used: 0.227 (sec). Leaf size: 45

DSolve[y''[x] == y[x]/f[x] - (x*y'[x])/f[x],y[x],x,IncludeSingularSolutions -> True]
                                                                                    
                                                                                    
 

\[ y(x)\to x \left (c_2 \int _1^x\frac {\exp \left (-\int _1^{K[2]}\frac {K[1]}{f(K[1])}dK[1]\right )}{K[2]^2}dK[2]+c_1\right ) \]