29.4 problem Ex 5

Internal problem ID [10261]

Book: An elementary treatise on differential equations by Abraham Cohen. DC heath publishers. 1906
Section: Chapter VII, Linear differential equations with constant coefficients. Article 52. Summary. Page 117
Problem number: Ex 5.
ODE order: 3.
ODE degree: 1.

CAS Maple gives this as type [[_3rd_order, _missing_y]]

\[ \boxed {y^{\prime \prime \prime }-4 y^{\prime }-x^{2}+3 \,{\mathrm e}^{2 x}=0} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 41

dsolve(diff(y(x),x$3)-4*diff(y(x),x)=x^2-3*exp(2*x),y(x), singsol=all)
 

\[ y \left (x \right ) = -\frac {x^{3}}{12}-\frac {c_{2} {\mathrm e}^{-2 x}}{2}-\frac {3 \,{\mathrm e}^{2 x} x}{8}+\frac {9 \,{\mathrm e}^{2 x}}{32}+\frac {{\mathrm e}^{2 x} c_{1}}{2}-\frac {x}{8}+c_{3} \]

Solution by Mathematica

Time used: 0.096 (sec). Leaf size: 49

DSolve[y'''[x]-4*y'[x]==x^2-3*Exp[2*x],y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to -\frac {1}{24} x \left (2 x^2+3\right )+\frac {1}{32} e^{2 x} (-12 x+9+16 c_1)-\frac {1}{2} c_2 e^{-2 x}+c_3 \\ \end{align*}