60.1.392 problem 403

Internal problem ID [10406]
Book : Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section : Chapter 1, linear first order
Problem number : 403
Date solved : Wednesday, March 05, 2025 at 10:44:59 AM
CAS classification : [_quadrature]

\begin{align*} a {y^{\prime }}^{2}+b y^{\prime }-y&=0 \end{align*}

Maple. Time used: 0.576 (sec). Leaf size: 207
ode:=a*diff(y(x),x)^2+b*diff(y(x),x)-y(x) = 0; 
dsolve(ode,y(x), singsol=all);
 
\begin{align*} y &= {\mathrm e}^{\frac {-b \operatorname {LambertW}\left (\frac {2 \,{\mathrm e}^{\frac {-c_{1} -b +x}{b}}}{b \sqrt {\frac {1}{a}}}\right )-b +x -c_{1}}{b}} \left (b \sqrt {\frac {1}{a}}+{\mathrm e}^{\frac {-b \operatorname {LambertW}\left (\frac {2 \,{\mathrm e}^{\frac {-c_{1} -b +x}{b}}}{b \sqrt {\frac {1}{a}}}\right )-b +x -c_{1}}{b}}\right ) \\ y &= \frac {b^{2} \left (\operatorname {LambertW}\left (-\frac {2 \sqrt {a}\, {\mathrm e}^{\frac {-c_{1} -b +x}{b}}}{b}\right )+2\right ) \operatorname {LambertW}\left (-\frac {2 \sqrt {a}\, {\mathrm e}^{\frac {-c_{1} -b +x}{b}}}{b}\right )}{4 a} \\ y &= \frac {b^{2} \left (\operatorname {LambertW}\left (\frac {2 \sqrt {a}\, {\mathrm e}^{\frac {-c_{1} -b +x}{b}}}{b}\right )+2\right ) \operatorname {LambertW}\left (\frac {2 \sqrt {a}\, {\mathrm e}^{\frac {-c_{1} -b +x}{b}}}{b}\right )}{4 a} \\ \end{align*}
Mathematica. Time used: 0.852 (sec). Leaf size: 123
ode=-y[x] + b*D[y[x],x] + a*D[y[x],x]^2==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 
\begin{align*} y(x)\to \text {InverseFunction}\left [\frac {\sqrt {4 \text {$\#$1} a+b^2}+b \log \left (a \left (\sqrt {4 \text {$\#$1} a+b^2}-b\right )\right )}{2 a}\&\right ]\left [\frac {x}{2 a}+c_1\right ] \\ y(x)\to \text {InverseFunction}\left [\frac {\sqrt {4 \text {$\#$1} a+b^2}-b \log \left (\sqrt {4 \text {$\#$1} a+b^2}+b\right )}{2 a}\&\right ]\left [-\frac {x}{2 a}+c_1\right ] \\ y(x)\to 0 \\ \end{align*}
Sympy. Time used: 1.181 (sec). Leaf size: 92
from sympy import * 
x = symbols("x") 
a = symbols("a") 
b = symbols("b") 
y = Function("y") 
ode = Eq(a*Derivative(y(x), x)**2 + b*Derivative(y(x), x) - y(x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 
\[ \left [ \begin {cases} - \frac {b \log {\left (b + \sqrt {4 a y{\left (x \right )} + b^{2}} \right )}}{2 a} + \frac {\sqrt {4 a y{\left (x \right )} + b^{2}}}{2 a} & \text {for}\: a \neq 0 \\\frac {y{\left (x \right )}}{b + \sqrt {b^{2}}} & \text {otherwise} \end {cases} = C_{1} - \frac {x}{2 a}, \ \frac {- b \log {\left (- b + \sqrt {4 a y{\left (x \right )} + b^{2}} \right )} + x - \sqrt {4 a y{\left (x \right )} + b^{2}}}{a} = C_{1}\right ] \]