8.6.34 problem 34 (a)

Internal problem ID [804]
Book : Differential equations and linear algebra, 3rd ed., Edwards and Penney
Section : Chapter 1 review problems. Page 78
Problem number : 34 (a)
Date solved : Monday, January 27, 2025 at 03:08:03 AM
CAS classification : [[_homogeneous, `class A`], _rational, [_Abel, `2nd type`, `class A`]]

\begin{align*} y^{\prime }&=\frac {x +3 y}{y-3 x} \end{align*}

Solution by Maple

Time used: 0.026 (sec). Leaf size: 51

dsolve(diff(y(x),x) = (x+3*y(x))/(-3*x+y(x)),y(x), singsol=all)
 
\begin{align*} y &= \frac {3 c_1 x -\sqrt {10 c_1^{2} x^{2}+1}}{c_1} \\ y &= \frac {3 c_1 x +\sqrt {10 c_1^{2} x^{2}+1}}{c_1} \\ \end{align*}

Solution by Mathematica

Time used: 0.423 (sec). Leaf size: 94

DSolve[D[y[x],x] == (x+3*y[x])/(-3*x+y[x]),y[x],x,IncludeSingularSolutions -> True]
 
\begin{align*} y(x)\to 3 x-\sqrt {10 x^2+e^{2 c_1}} \\ y(x)\to 3 x+\sqrt {10 x^2+e^{2 c_1}} \\ y(x)\to 3 x-\sqrt {10} \sqrt {x^2} \\ y(x)\to \sqrt {10} \sqrt {x^2}+3 x \\ \end{align*}