[[_high_order, _linear, _nonhomogeneous]]
Book solution method
TO DO
Mathematica ✓
cpu = 0.00844123 (sec), leaf count = 45
Maple ✓
cpu = 0.026 (sec), leaf count = 38
DSolve[y''''[x] == x^3 + a^4*y[x],y[x],x]
Mathematica raw output
{{y[x] -> -(x^3/a^4) + C[2]/E^(a*x) + E^(a*x)*C[4] + C[1]*Cos[a*x] + C[3]*Sin[a*
x]}}
Maple raw input
dsolve(diff(diff(diff(diff(y(x),x),x),x),x) = x^3+a^4*y(x), y(x),'implicit')
Maple raw output
y(x) = -1/a^4*x^3+_C1*cos(a*x)+_C2*exp(a*x)+_C3*sin(a*x)+_C4*exp(-a*x)