82.5.2 problem Ex. 2

Internal problem ID [18738]
Book : Introductory Course On Differential Equations by Daniel A Murray. Longmans Green and Co. NY. 1924
Section : Chapter II. Equations of the first order and of the first degree. Exercises at page 20
Problem number : Ex. 2
Date solved : Tuesday, January 28, 2025 at 12:13:55 PM
CAS classification : [[_1st_order, _with_linear_symmetries], _exact, _rational]

\begin{align*} x +y^{\prime } y+\frac {-y+x y^{\prime }}{x^{2}+y^{2}}&=0 \end{align*}

✓ Solution by Maple

Time used: 0.072 (sec). Leaf size: 26

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

\[ y \left (x \right ) = \cot \left (\operatorname {RootOf}\left (2 c_{1} \sin \left (\textit {\_Z} \right )^{2}-2 \sin \left (\textit {\_Z} \right )^{2} \textit {\_Z} +x^{2}\right )\right ) x \]

✓ Solution by Mathematica

Time used: 0.113 (sec). Leaf size: 31

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

\[ \text {Solve}\left [-\arctan \left (\frac {x}{y(x)}\right )+\frac {x^2}{2}+\frac {y(x)^2}{2}=c_1,y(x)\right ] \]