21.1 problem 696

Internal problem ID [15440]

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 ODE’s). Section 16. The method of isoclines for differential equations of the second order. Exercises page 158
Problem number: 696.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _missing_x]]

\[ \boxed {x^{\prime \prime }+x^{\prime }+x=0} \]

Solution by Maple

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

dsolve(diff(x(t),t$2)+diff(x(t),t)+x(t)=0,x(t), singsol=all)
 

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

Solution by Mathematica

Time used: 0.022 (sec). Leaf size: 42

DSolve[x''[t]+x'[t]+x[t]==0,x[t],t,IncludeSingularSolutions -> True]
 

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