4.6 problem Problem 14

Internal problem ID [2670]

Book: Differential equations and linear algebra, Stephen W. Goode and Scott A Annin. Fourth edition, 2015
Section: Chapter 1, First-Order Differential Equations. Section 1.8, Change of Variables. page 79
Problem number: Problem 14.
ODE order: 1.
ODE degree: 1.

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

\[ \boxed {x y^{\prime }-y-\sqrt {9 x^{2}+y^{2}}=0} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 28

dsolve(x*diff(y(x),x)-y(x)=sqrt(9*x^2+y(x)^2),y(x), singsol=all)
 

\[ \frac {-c_{1} x^{2}+\sqrt {9 x^{2}+y \left (x \right )^{2}}+y \left (x \right )}{x^{2}} = 0 \]

Solution by Mathematica

Time used: 0.35 (sec). Leaf size: 27

DSolve[x*y'[x]-y[x]==Sqrt[9*x^2+y[x]^2],y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {9 e^{c_1} x^2}{2}-\frac {e^{-c_1}}{2} \]