Internal problem ID [6137]
Book: Elementary differential equations. Rainville, Bedient, Bedient. Prentice Hall. NJ. 8th edition.
1997.
Section: CHAPTER 17. Power series solutions. 17.5. Solutions Near an Ordinary Point. Exercises page
355
Problem number: 2.
ODE order: 2.
ODE degree: 1.
CAS Maple gives this as type [[_2nd_order, _missing_x]]
Solve \begin {gather*} \boxed {y^{\prime \prime }-9 y=0} \end {gather*} With the expansion point for the power series method at \(x = 0\).
✓ Solution by Maple
Time used: 0.002 (sec). Leaf size: 44
Order:=8; dsolve(diff(y(x),x$2)-9*y(x)=0,y(x),type='series',x=0);
\[ y \relax (x ) = \left (1+\frac {9}{2} x^{2}+\frac {27}{8} x^{4}+\frac {81}{80} x^{6}\right ) y \relax (0)+\left (x +\frac {3}{2} x^{3}+\frac {27}{40} x^{5}+\frac {81}{560} x^{7}\right ) D\relax (y )\relax (0)+O\left (x^{8}\right ) \]
✓ Solution by Mathematica
Time used: 0.001 (sec). Leaf size: 56
AsymptoticDSolveValue[y''[x]-9*y[x]==0,y[x],{x,0,7}]
\[ y(x)\to c_2 \left (\frac {81 x^7}{560}+\frac {27 x^5}{40}+\frac {3 x^3}{2}+x\right )+c_1 \left (\frac {81 x^6}{80}+\frac {27 x^4}{8}+\frac {9 x^2}{2}+1\right ) \]