2.20 problem Problem 20

Internal problem ID [10835]

Book: Differential equations and the calculus of variations by L. ElSGOLTS. MIR PUBLISHERS, MOSCOW, Third printing 1977.
Section: Chapter 2, DIFFERENTIAL EQUATIONS OF THE SECOND ORDER AND HIGHER. Problems page 172
Problem number: Problem 20.
ODE order: 2.
ODE degree: 1.

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

\[ \boxed {u^{\prime \prime }+\frac {2 u^{\prime }}{r}=0} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 11

dsolve(diff(u(r),r$2)+2/r*diff(u(r),r)=0,u(r), singsol=all)
 

\[ u \left (r \right ) = c_{1} +\frac {c_{2}}{r} \]

Solution by Mathematica

Time used: 0.012 (sec). Leaf size: 15

DSolve[u''[r]+2/r*u'[r]==0,u[r],r,IncludeSingularSolutions -> True]
 

\begin{align*} u(r)\to c_2-\frac {c_1}{r} \\ \end{align*}