17.46 problem 46

Internal problem ID [13524]

Book: Ordinary Differential Equations. An introduction to the fundamentals. Kenneth B. Howell. second edition. CRC Press. FL, USA. 2020
Section: Chapter 25. Review exercises for part III. page 447
Problem number: 46.
ODE order: 2.
ODE degree: 1.

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

\[ \boxed {3 y^{\prime \prime }+8 y^{\prime }-3 y=123 x \sin \left (3 x \right )} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 39

dsolve(3*diff(y(x),x$2)+8*diff(y(x),x)-3*y(x)=123*x*sin(3*x),y(x), singsol=all)
 

\[ y \left (x \right ) = {\mathrm e}^{-3 x} c_{2} +{\mathrm e}^{\frac {x}{3}} c_{1} +\frac {\left (-492 x -241\right ) \cos \left (3 x \right )}{246}+\frac {\left (-615 x +324\right ) \sin \left (3 x \right )}{246} \]

Solution by Mathematica

Time used: 0.027 (sec). Leaf size: 50

DSolve[3*y''[x]+8*y'[x]-3*y[x]==123*x*Sin[3*x],y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \left (\frac {54}{41}-\frac {5 x}{2}\right ) \sin (3 x)+\left (-2 x-\frac {241}{246}\right ) \cos (3 x)+c_1 e^{x/3}+c_2 e^{-3 x} \]