2.12.3.8 problem 208 out of 373

Link to actual problem [8675] \[ \boxed {\left (x \sqrt {x^{2}+y^{2}+1}-y \left (x^{2}+y^{2}\right )\right ) y^{\prime }-y \sqrt {x^{2}+y^{2}+1}-x \left (x^{2}+y^{2}\right )=0} \]

type detected by program

{"first_order_ode_lie_symmetry_calculated"}

type detected by Maple

[[_1st_order, _with_linear_symmetries]]

Maple symgen result This shows Maple’s found \(\xi ,\eta \) and the corresponding canonical coordinates \(R,S\)\begin{align*} \\ \left [R &= x^{2}+y^{2}, S \left (R \right ) &= -\arctan \left (\frac {x}{y}\right )\right ] \\ \end{align*}

My program’s symgen result This shows my program’s found \(\xi ,\eta \) and the corresponding ODE in canonical coordinates \(R,S\).\begin{align*} \xi &= 0 \\ \eta &=\frac {x^{2} \sqrt {x^{2}+y^{2}+1}+y^{2} \sqrt {x^{2}+y^{2}+1}}{-x^{2} y -y^{3}+x \sqrt {x^{2}+y^{2}+1}} \\ \frac {dS}{dR} &= 0 \\ \end{align*}