1.41 problem 42

Internal problem ID [3186]

Book: Differential equations for engineers by Wei-Chau XIE, Cambridge Press 2010
Section: Chapter 2. First-Order and Simple Higher-Order Differential Equations. Page 78
Problem number: 42.
ODE order: 1.
ODE degree: 1.

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

\[ \boxed {-\sqrt {y^{2}+x^{2}}+\left (y-\sqrt {y^{2}+x^{2}}\right ) y^{\prime }=-x} \]

Solution by Maple

Time used: 0.047 (sec). Leaf size: 58

dsolve((x-sqrt(x^2+y(x)^2))+(y(x)-sqrt(x^2+y(x)^2))*diff(y(x),x)=0,y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 0.834 (sec). Leaf size: 34

DSolve[(x-Sqrt[x^2+y[x]^2])+(y[x]-Sqrt[x^2+y[x]^2])*y'[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to -\frac {e^{c_1} \left (2 x+e^{c_1}\right )}{2 \left (x+e^{c_1}\right )} y(x)\to 0 \end{align*}