75.21.3 problem 698

Internal problem ID [17172]
Book : A book of problems in ordinary differential equations. M.L. KRASNOV, A.L. KISELYOV, G.I. MARKARENKO. MIR, MOSCOW. 1983
Section : Chapter 2 (Higher order ODEs). Section 16. The method of isoclines for differential equations of the second order. Exercises page 158
Problem number : 698
Date solved : Tuesday, January 28, 2025 at 09:56:05 AM
CAS classification : [[_2nd_order, _missing_x]]

\begin{align*} x^{\prime \prime }+2 x^{\prime }+x&=0 \end{align*}

Solution by Maple

Time used: 0.003 (sec). Leaf size: 14

dsolve(diff(x(t),t$2)+2*diff(x(t),t)+x(t)=0,x(t), singsol=all)
 
\[ x \left (t \right ) = {\mathrm e}^{-t} \left (c_{2} t +c_{1} \right ) \]

Solution by Mathematica

Time used: 0.014 (sec). Leaf size: 18

DSolve[D[x[t],{t,2}]+2*D[x[t],t]+x[t]==0,x[t],t,IncludeSingularSolutions -> True]
 
\[ x(t)\to e^{-t} (c_2 t+c_1) \]