ODE
\[ y'''(x)+y''(x)+y'(x)-3 y(x)=0 \] ODE Classification
[[_3rd_order, _missing_x]]
Book solution method
TO DO
Mathematica ✓
cpu = 0.157646 (sec), leaf count = 42
\[\left \{\left \{y(x)\to e^{-x} \left (c_3 e^{2 x}+c_2 \cos \left (\sqrt {2} x\right )+c_1 \sin \left (\sqrt {2} x\right )\right )\right \}\right \}\]
Maple ✓
cpu = 0.012 (sec), leaf count = 33
\[\left [y \left (x \right ) = \textit {\_C1} \,{\mathrm e}^{x}+\textit {\_C2} \,{\mathrm e}^{-x} \sin \left (\sqrt {2}\, x \right )+\textit {\_C3} \,{\mathrm e}^{-x} \cos \left (\sqrt {2}\, x \right )\right ]\] Mathematica raw input
DSolve[-3*y[x] + y'[x] + y''[x] + y'''[x] == 0,y[x],x]
Mathematica raw output
{{y[x] -> (E^(2*x)*C[3] + C[2]*Cos[Sqrt[2]*x] + C[1]*Sin[Sqrt[2]*x])/E^x}}
Maple raw input
dsolve(diff(diff(diff(y(x),x),x),x)+diff(diff(y(x),x),x)+diff(y(x),x)-3*y(x) = 0, y(x))
Maple raw output
[y(x) = _C1*exp(x)+_C2*exp(-x)*sin(2^(1/2)*x)+_C3*exp(-x)*cos(2^(1/2)*x)]