ODE
\[ y'''(x)+2 y''(x)+y'(x)=0 \] ODE Classification
[[_3rd_order, _missing_x]]
Book solution method
TO DO
Mathematica ✓
cpu = 0.176476 (sec), leaf count = 24
\[\left \{\left \{y(x)\to c_3-e^{-x} (c_2 (x+1)+c_1)\right \}\right \}\]
Maple ✓
cpu = 0.013 (sec), leaf count = 19
\[[y \left (x \right ) = \textit {\_C1} +\textit {\_C2} \,{\mathrm e}^{-x}+\textit {\_C3} \,{\mathrm e}^{-x} x]\] Mathematica raw input
DSolve[y'[x] + 2*y''[x] + y'''[x] == 0,y[x],x]
Mathematica raw output
{{y[x] -> -((C[1] + (1 + x)*C[2])/E^x) + C[3]}}
Maple raw input
dsolve(diff(diff(diff(y(x),x),x),x)+2*diff(diff(y(x),x),x)+diff(y(x),x) = 0, y(x))
Maple raw output
[y(x) = _C1+_C2*exp(-x)+_C3*exp(-x)*x]