16.15 problem 458

Internal problem ID [3204]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 16
Problem number: 458.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [[_homogeneous, class G], _rational, [_Abel, 2nd type, class A]]

Solve \begin {gather*} \boxed {\left (x^{2}-y\right ) y^{\prime }-4 y x=0} \end {gather*}

Solution by Maple

Time used: 0.047 (sec). Leaf size: 53

dsolve((x^2-y(x))*diff(y(x),x) = 4*x*y(x),y(x), singsol=all)
 

\begin{align*} y \relax (x ) = \frac {c_{1} \left (c_{1}-\sqrt {-4 x^{2}+c_{1}^{2}}\right )}{2}-x^{2} \\ y \relax (x ) = \frac {c_{1} \left (c_{1}+\sqrt {-4 x^{2}+c_{1}^{2}}\right )}{2}-x^{2} \\ \end{align*}

Solution by Mathematica

Time used: 2.354 (sec). Leaf size: 206

DSolve[(x^2-y[x])y'[x]==4 x y[x],y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to x^2 \left (1+\frac {2-2 i}{\frac {i \sqrt {2}}{\sqrt {e^{\frac {2 c_1}{9}} x^2-i}}-(1-i)}\right ) \\ y(x)\to x^2 \left (1+\frac {2-2 i}{(-1+i)-\frac {i \sqrt {2}}{\sqrt {e^{\frac {2 c_1}{9}} x^2-i}}}\right ) \\ y(x)\to x^2 \left (1+\frac {2-2 i}{(-1+i)-\frac {\sqrt {2}}{\sqrt {e^{\frac {2 c_1}{9}} x^2+i}}}\right ) \\ y(x)\to x^2 \left (1+\frac {2-2 i}{\frac {\sqrt {2}}{\sqrt {e^{\frac {2 c_1}{9}} x^2+i}}-(1-i)}\right ) \\ y(x)\to 0 \\ y(x)\to -x^2 \\ \end{align*}