78.18.6 problem 6

Internal problem ID [18418]
Book : DIFFERENTIAL EQUATIONS WITH APPLICATIONS AND HISTORICAL NOTES by George F. Simmons. 3rd edition. 2017. CRC press, Boca Raton FL.
Section : Chapter 5. Power Series Solutions and Special Functions. Section 28. Second Order Linear Equations. Ordinary Points. Problems at page 217
Problem number : 6
Date solved : Tuesday, January 28, 2025 at 11:49:42 AM
CAS classification : [_Gegenbauer, [_2nd_order, _linear, `_with_symmetry_[0,F(x)]`]]

\begin{align*} \left (-x^{2}+1\right ) y^{\prime \prime }-x y^{\prime }+n^{2} y&=0 \end{align*}

Using series method with expansion around

\begin{align*} 0 \end{align*}

✓ Solution by Maple

Time used: 0.004 (sec). Leaf size: 65

Order:=6; 
dsolve((1-x^2)*diff(y(x),x$2)-x*diff(y(x),x)+n^2*y(x)=0,y(x),type='series',x=0);
 

\[ y = \left (1-\frac {n^{2} x^{2}}{2}+\frac {n^{2} \left (n^{2}-4\right ) x^{4}}{24}\right ) y \left (0\right )+\left (x -\frac {\left (n^{2}-1\right ) x^{3}}{6}+\frac {\left (n^{4}-10 n^{2}+9\right ) x^{5}}{120}\right ) y^{\prime }\left (0\right )+O\left (x^{6}\right ) \]

✓ Solution by Mathematica

Time used: 0.001 (sec). Leaf size: 88

AsymptoticDSolveValue[(1-x^2)*D[y[x],{x,2}]-x*D[y[x],x]+n^2*y[x]==0,y[x],{x,0,"6"-1}]
 

\[ y(x)\to c_2 \left (\frac {n^4 x^5}{120}-\frac {n^2 x^5}{12}-\frac {n^2 x^3}{6}+\frac {3 x^5}{40}+\frac {x^3}{6}+x\right )+c_1 \left (\frac {n^4 x^4}{24}-\frac {n^2 x^4}{6}-\frac {n^2 x^2}{2}+1\right ) \]