[[_Emden, _Fowler]]
Book solution method
TO DO
Mathematica ✓
cpu = 0.0665238 (sec), leaf count = 57
Maple ✓
cpu = 0.033 (sec), leaf count = 23
DSolve[a^2*y[x] + x^4*y''[x] == 0,y[x],x]
Mathematica raw output
{{y[x] -> E^(Sqrt[-a^2]/x)*x*C[1] + (x*C[2])/(2*Sqrt[-a^2]*E^(Sqrt[-a^2]/x))}}
Maple raw input
dsolve(x^4*diff(diff(y(x),x),x)+a^2*y(x) = 0, y(x),'implicit')
Maple raw output
y(x) = x*(cos(1/x*a)*_C2+sin(1/x*a)*_C1)