50.5.8 problem 1(h)

Internal problem ID [7878]
Book : Differential Equations: Theory, Technique, and Practice by George Simmons, Steven Krantz. McGraw-Hill NY. 2007. 1st Edition.
Section : Chapter 1. What is a differential equation. Section 1.7. Homogeneous Equations. Page 28
Problem number : 1(h)
Date solved : Monday, January 27, 2025 at 03:30:18 PM
CAS classification : [[_homogeneous, `class A`], _rational, _dAlembert]

\begin{align*} x y^{\prime }&=\sqrt {x^{2}+y^{2}} \end{align*}

Solution by Maple

Time used: 0.005 (sec). Leaf size: 51

dsolve(x*diff(y(x),x)=sqrt(x^2+y(x)^2),y(x), singsol=all)
 
\[ \frac {y^{2}+y \sqrt {x^{2}+y^{2}}+x^{2} \left (\ln \left (y+\sqrt {x^{2}+y^{2}}\right )-c_{1} -3 \ln \left (x \right )\right )}{x^{2}} = 0 \]

Solution by Mathematica

Time used: 0.272 (sec). Leaf size: 66

DSolve[x*D[y[x],x]==Sqrt[x^2+y[x]^2],y[x],x,IncludeSingularSolutions -> True]
 
\[ \text {Solve}\left [\frac {1}{2} \left (\frac {y(x) \left (\sqrt {\frac {y(x)^2}{x^2}+1}+\frac {y(x)}{x}\right )}{x}-\log \left (\sqrt {\frac {y(x)^2}{x^2}+1}-\frac {y(x)}{x}\right )\right )=\log (x)+c_1,y(x)\right ] \]