4.20.18 \(-\left (x^2-y(x)^2\right ) y'(x)+x y(x) y'(x)^2-x y(x)=0\)

ODE
\[ -\left (x^2-y(x)^2\right ) y'(x)+x y(x) y'(x)^2-x y(x)=0 \] ODE Classification

[_separable]

Book solution method
No Missing Variables ODE, Solve for \(y'\)

Mathematica
cpu = 0.00654564 (sec), leaf count = 45

\[\left \{\left \{y(x)\to \frac {c_1}{x}\right \},\left \{y(x)\to -\sqrt {2 c_1+x^2}\right \},\left \{y(x)\to \sqrt {2 c_1+x^2}\right \}\right \}\]

Maple
cpu = 0.01 (sec), leaf count = 24

\[ \left \{ -{x}^{2}+ \left ( y \left ( x \right ) \right ) ^{2}-{\it \_C1}=0,y \left ( x \right ) ={\frac {{\it \_C1}}{x}} \right \} \] Mathematica raw input

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

Mathematica raw output

{{y[x] -> C[1]/x}, {y[x] -> -Sqrt[x^2 + 2*C[1]]}, {y[x] -> Sqrt[x^2 + 2*C[1]]}}

Maple raw input

dsolve(x*y(x)*diff(y(x),x)^2-(x^2-y(x)^2)*diff(y(x),x)-x*y(x) = 0, y(x),'implicit')

Maple raw output

y(x) = _C1/x, -x^2+y(x)^2-_C1 = 0