9.5 problem 1(e)

Internal problem ID [11456]

Book: A First Course in Differential Equations by J. David Logan. Third Edition. Springer-Verlag, NY. 2015.
Section: Chapter 2, Second order linear equations. Section 2.3.1 Nonhomogeneous Equations: Undetermined Coefficients. Exercises page 110
Problem number: 1(e).
ODE order: 2.
ODE degree: 1.

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

\[ \boxed {x^{\prime \prime }+x^{\prime }+x=5 \sin \left (7 t \right )} \]

Solution by Maple

Time used: 0.015 (sec). Leaf size: 43

dsolve(diff(x(t),t$2)+diff(x(t),t)+x(t)=5*sin(7*t),x(t), singsol=all)
 

\[ x \left (t \right ) = {\mathrm e}^{-\frac {t}{2}} \sin \left (\frac {\sqrt {3}\, t}{2}\right ) c_{2} +{\mathrm e}^{-\frac {t}{2}} \cos \left (\frac {\sqrt {3}\, t}{2}\right ) c_{1} -\frac {240 \sin \left (7 t \right )}{2353}-\frac {35 \cos \left (7 t \right )}{2353} \]

Solution by Mathematica

Time used: 0.046 (sec). Leaf size: 65

DSolve[x''[t]+x'[t]+x[t]==5*Sin[7*t],x[t],t,IncludeSingularSolutions -> True]
 

\[ x(t)\to -\frac {5 (48 \sin (7 t)+7 \cos (7 t))}{2353}+c_2 e^{-t/2} \cos \left (\frac {\sqrt {3} t}{2}\right )+c_1 e^{-t/2} \sin \left (\frac {\sqrt {3} t}{2}\right ) \]