29.14.10 problem 391

Internal problem ID [4989]
Book : Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section : Various 14
Problem number : 391
Date solved : Sunday, March 30, 2025 at 04:28:36 AM
CAS classification : [_separable]

\begin{align*} \left (x -\sqrt {x^{2}+1}\right ) y^{\prime }&=y+\sqrt {1+y^{2}} \end{align*}

Maple. Time used: 0.002 (sec). Leaf size: 39
ode:=(x-(x^2+1)^(1/2))*diff(y(x),x) = y(x)+(1+y(x)^2)^(1/2); 
dsolve(ode,y(x), singsol=all);
 
\[ c_1 +x^{2}+x \sqrt {x^{2}+1}+\operatorname {arcsinh}\left (x \right )+y \sqrt {1+y^{2}}+\operatorname {arcsinh}\left (y\right )-y^{2} = 0 \]
Mathematica. Time used: 0.883 (sec). Leaf size: 84
ode=(x-Sqrt[1+x^2])D[y[x],x]==y[x]+Sqrt[1+ y[x]^2]; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 
\[ y(x)\to \text {InverseFunction}\left [\frac {1}{2} \left (\text {$\#$1} \left (\sqrt {\text {$\#$1}^2+1}-\text {$\#$1}\right )-\log \left (\sqrt {\text {$\#$1}^2+1}-\text {$\#$1}\right )\right )\&\right ]\left [\frac {1}{2} \left (\log \left (\sqrt {x^2+1}-x\right )-x \left (\sqrt {x^2+1}+x\right )\right )+c_1\right ] \]
Sympy. Time used: 1.666 (sec). Leaf size: 138
from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq((x - sqrt(x**2 + 1))*Derivative(y(x), x) - sqrt(y(x)**2 + 1) - y(x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 
\[ \frac {x \operatorname {asinh}{\left (x \right )}}{2 \left (x - \sqrt {x^{2} + 1}\right )} - \frac {x}{2 \left (x - \sqrt {x^{2} + 1}\right )} + \frac {\sqrt {y^{2}{\left (x \right )} + 1} \operatorname {asinh}{\left (y{\left (x \right )} \right )}}{2 \left (\sqrt {y^{2}{\left (x \right )} + 1} + y{\left (x \right )}\right )} + \frac {y{\left (x \right )} \operatorname {asinh}{\left (y{\left (x \right )} \right )}}{2 \left (\sqrt {y^{2}{\left (x \right )} + 1} + y{\left (x \right )}\right )} + \frac {y{\left (x \right )}}{2 \left (\sqrt {y^{2}{\left (x \right )} + 1} + y{\left (x \right )}\right )} - \frac {\sqrt {x^{2} + 1} \operatorname {asinh}{\left (x \right )}}{2 \left (x - \sqrt {x^{2} + 1}\right )} = C_{1} \]