7.12 problem Problem 36

Internal problem ID [2247]

Book: Differential equations and linear algebra, Stephen W. Goode and Scott A Annin. Fourth edition, 2015
Section: Chapter 8, Linear differential equations of order n. Section 8.3, The Method of Undetermined Coefficients. page 525
Problem number: Problem 36.
ODE order: 2.
ODE degree: 1.

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

Solve \begin {gather*} \boxed {y^{\prime \prime }+y^{\prime }-2 y-4 \cos \relax (x )+2 \sin \relax (x )=0} \end {gather*} With initial conditions \begin {align*} [y \relax (0) = -1, y^{\prime }\relax (0) = 4] \end {align*}

Solution by Maple

Time used: 0.026 (sec). Leaf size: 19

dsolve([diff(y(x),x$2)+diff(y(x),x)-2*y(x)=4*cos(x)-2*sin(x),y(0) = -1, D(y)(0) = 4],y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 0.034 (sec). Leaf size: 22

DSolve[{y''[x]+y'[x]-2*y[x]==4*Cos[x]-2*Sin[x],{y[0]==-1,y'[0]==4}},y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to -e^{-2 x}+e^x+\sin (x)-\cos (x) \\ \end{align*}