77.1.71 problem 90 (b)(page 123)

Internal problem ID [17882]
Book : V.V. Stepanov, A course of differential equations (in Russian), GIFML. Moscow (1958)
Section : All content
Problem number : 90 (b)(page 123)
Date solved : Thursday, March 13, 2025 at 11:08:23 AM
CAS classification : [[_1st_order, _with_linear_symmetries], _Clairaut]

\begin{align*} y^{\prime }&=-x -\sqrt {x^{2}+2 y} \end{align*}

✓ Maple. Time used: 0.099 (sec). Leaf size: 18

ode:=diff(y(x),x) = -x-(x^2+2*y(x))^(1/2); 
dsolve(ode,y(x), singsol=all);
 

\[ x +\sqrt {x^{2}+2 y}-c_{1} = 0 \]

✓ Mathematica. Time used: 0.924 (sec). Leaf size: 46

ode=D[y[x],x]==-x-Sqrt[x^2+2*y[x]]; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 

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

✓ Sympy. Time used: 0.684 (sec). Leaf size: 10

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(x + sqrt(x**2 + 2*y(x)) + Derivative(y(x), x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 

\[ y{\left (x \right )} = \frac {C_{1} \left (C_{1} + 2 x\right )}{2} \]