27.4 problem Ex 4

Internal problem ID [11276]

Book: An elementary treatise on differential equations by Abraham Cohen. DC heath publishers. 1906
Section: Chapter VII, Linear differential equations with constant coefficients. Article 50. Method of undetermined coefficients. Page 107
Problem number: Ex 4.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _linear, _nonhomogeneous]]

\[ \boxed {y^{\prime \prime }+2 y^{\prime }+y=3 \,{\mathrm e}^{2 x}-\cos \left (x \right )} \]

Solution by Maple

Time used: 0.015 (sec). Leaf size: 28

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

\[ y \left (x \right ) = c_{2} {\mathrm e}^{-x}+{\mathrm e}^{-x} x c_{1} +\frac {{\mathrm e}^{2 x}}{3}-\frac {\sin \left (x \right )}{2} \]

Solution by Mathematica

Time used: 0.454 (sec). Leaf size: 38

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

\[ y(x)\to \frac {1}{6} e^{-x} \left (2 e^{3 x}-3 e^x \sin (x)+6 c_2 x+6 c_1\right ) \]