1.3 problem Problem 3

Internal problem ID [12114]

Book: Differential equations and the calculus of variations by L. ElSGOLTS. MIR PUBLISHERS, MOSCOW, Third printing 1977.
Section: Chapter 1, First-Order Differential Equations. Problems page 88
Problem number: Problem 3.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [[_homogeneous, `class A`], _rational, _dAlembert]

\[ \boxed {y^{\prime } x -y-\sqrt {x^{2}+y^{2}}=0} \]

Solution by Maple

Time used: 0.015 (sec). Leaf size: 26

dsolve(x*diff(y(x),x)=y(x)+sqrt(x^2+y(x)^2),y(x), singsol=all)
 

\[ \frac {-c_{1} x^{2}+y \left (x \right )+\sqrt {y \left (x \right )^{2}+x^{2}}}{x^{2}} = 0 \]

Solution by Mathematica

Time used: 0.603 (sec). Leaf size: 27

DSolve[x*y'[x]==y[x]+Sqrt[x^2+y[x]^2],y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {1}{2} e^{-c_1} \left (-1+e^{2 c_1} x^2\right ) \]