15.23 problem 23

Internal problem ID [11924]

Book: Differential Equations by Shepley L. Ross. Third edition. John Willey. New Delhi. 2004.
Section: Chapter 6, Series solutions of linear differential equations. Section 6.2 (Frobenius). Exercises page 251
Problem number: 23.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_Emden, _Fowler]]

\[ \boxed {x y^{\prime \prime }+y^{\prime }+2 y=0} \] With the expansion point for the power series method at \(x = 0\).

Solution by Maple

Time used: 0.032 (sec). Leaf size: 59

Order:=6; 
dsolve(x*diff(y(x),x$2)+diff(y(x),x)+2*y(x)=0,y(x),type='series',x=0);
 

\[ y \left (x \right ) = \left (c_{1} +c_{2} \ln \left (x \right )\right ) \left (1-2 x +x^{2}-\frac {2}{9} x^{3}+\frac {1}{36} x^{4}-\frac {1}{450} x^{5}+\operatorname {O}\left (x^{6}\right )\right )+\left (4 x -3 x^{2}+\frac {22}{27} x^{3}-\frac {25}{216} x^{4}+\frac {137}{13500} x^{5}+\operatorname {O}\left (x^{6}\right )\right ) c_{2} \]

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 101

AsymptoticDSolveValue[x*y''[x]+y'[x]+2*y[x]==0,y[x],{x,0,5}]
 

\[ y(x)\to c_1 \left (-\frac {x^5}{450}+\frac {x^4}{36}-\frac {2 x^3}{9}+x^2-2 x+1\right )+c_2 \left (\frac {137 x^5}{13500}-\frac {25 x^4}{216}+\frac {22 x^3}{27}-3 x^2+\left (-\frac {x^5}{450}+\frac {x^4}{36}-\frac {2 x^3}{9}+x^2-2 x+1\right ) \log (x)+4 x\right ) \]