2.3.19 Problem 20
Internal
problem
ID
[13299]
Book
:
Handbook
of
exact
solutions
for
ordinary
differential
equations.
By
Polyanin
and
Zaitsev.
Second
edition
Section
:
Chapter
1,
section
1.2.
Riccati
Equation.
subsection
1.2.3.
Equations
Containing
Exponential
Functions
Problem
number
:
20
Date
solved
:
Wednesday, December 31, 2025 at 01:03:11 PM
CAS
classification
:
[_Riccati]
2.3.19.1 Solved using first_order_ode_riccati_by_guessing_particular_solution
0.674 (sec)
Entering first order ode riccati guess solver
\begin{align*}
\left ({\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c \right ) y^{\prime }&=y^{2}+k \,{\mathrm e}^{\nu x} y-m^{2}+k m \,{\mathrm e}^{\nu x} \\
\end{align*}
This is a Riccati ODE. Comparing the above ODE to
solve with the Riccati standard form \[ y' = f_0(x)+ f_1(x)y+f_2(x)y^{2} \]
Shows that \begin{align*} f_0(x) & =\frac {k m \,{\mathrm e}^{\nu x}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}-\frac {m^{2}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}\\ f_1(x) & =\frac {k \,{\mathrm e}^{\nu x}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}\\ f_2(x) &=\frac {1}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c} \end{align*}
Using trial and error, the following particular solution was found
\[
y_p = -m
\]
Since a particular solution is
known, then the general solution is given by \begin{align*} y &= y_p + \frac { \phi (x) }{ c_1 - \int { \phi (x) f_2 \,dx} } \end{align*}
Where
\begin{align*} \phi (x) &= e^{ \int 2 f_2 y_p + f_1 \,dx } \end{align*}
Evaluating the above gives the general solution as
\[
y = -m +\frac {{\mathrm e}^{\int \left (\frac {k \,{\mathrm e}^{\nu x}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}-\frac {2 m}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}\right )d x}}{c_1 -\int \frac {{\mathrm e}^{\int \left (\frac {k \,{\mathrm e}^{\nu x}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}-\frac {2 m}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}\right )d x}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}d x}
\]
Summary of solutions found
\begin{align*}
y &= -m +\frac {{\mathrm e}^{\int \left (\frac {k \,{\mathrm e}^{\nu x}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}-\frac {2 m}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}\right )d x}}{c_1 -\int \frac {{\mathrm e}^{\int \left (\frac {k \,{\mathrm e}^{\nu x}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}-\frac {2 m}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}\right )d x}}{{\mathrm e}^{\lambda x} a +{\mathrm e}^{\mu x} b +c}d x} \\
\end{align*}
2.3.19.2 ✓ Maple. Time used: 0.009 (sec). Leaf size: 130
ode:=(a*exp(lambda*x)+b*exp(mu*x)+c)*diff(y(x),x) = y(x)^2+k*exp(nu*x)*y(x)-m^2+k*m*exp(nu*x);
dsolve(ode,y(x), singsol=all);
\[
y = -m +\frac {{\mathrm e}^{k \int \frac {{\mathrm e}^{\nu x}}{a \,{\mathrm e}^{\lambda x}+b \,{\mathrm e}^{\mu x}+c}d x -2 m \int \frac {1}{a \,{\mathrm e}^{\lambda x}+b \,{\mathrm e}^{\mu x}+c}d x}}{-\int \frac {{\mathrm e}^{k \int \frac {{\mathrm e}^{\nu x}}{a \,{\mathrm e}^{\lambda x}+b \,{\mathrm e}^{\mu x}+c}d x -2 m \int \frac {1}{a \,{\mathrm e}^{\lambda x}+b \,{\mathrm e}^{\mu x}+c}d x}}{a \,{\mathrm e}^{\lambda x}+b \,{\mathrm e}^{\mu x}+c}d x +c_1}
\]
Maple trace
Methods for first order ODEs:
--- Trying classification methods ---
trying a quadrature
trying 1st order linear
trying Bernoulli
trying separable
trying inverse linear
trying homogeneous types:
trying Chini
differential order: 1; looking for linear symmetries
trying exact
Looking for potential symmetries
trying Riccati
trying Riccati sub-methods:
<- Riccati particular case Kamke (b) successful
Maple step by step
\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & \left (a \,{\mathrm e}^{\lambda x}+b \,{\mathrm e}^{\mu x}+c \right ) \left (\frac {d}{d x}y \left (x \right )\right )=y \left (x \right )^{2}+k \,{\mathrm e}^{\nu x} y \left (x \right )-m^{2}+k m \,{\mathrm e}^{\nu x} \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & \frac {d}{d x}y \left (x \right ) \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & \frac {d}{d x}y \left (x \right )=\frac {y \left (x \right )^{2}+k \,{\mathrm e}^{\nu x} y \left (x \right )-m^{2}+k m \,{\mathrm e}^{\nu x}}{a \,{\mathrm e}^{\lambda x}+b \,{\mathrm e}^{\mu x}+c} \end {array} \]
2.3.19.3 ✓ Mathematica. Time used: 3.73 (sec). Leaf size: 358
ode=(a*Exp[\[Lambda]*x]+b*Exp[\[Mu]*x]+c)*D[y[x],x]==y[x]^2+k*Exp[\[Nu]*x]*y[x]-m^2+k*m*Exp[\[Nu]*x];
ic={};
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
\[
\text {Solve}\left [\int _1^x-\frac {\exp \left (-\int _1^{K[2]}-\frac {e^{\nu K[1]} k-2 m}{e^{\lambda K[1]} a+b e^{\mu K[1]}+c}dK[1]\right ) \left (e^{\nu K[2]} k-m+y(x)\right )}{\left (e^{\lambda K[2]} a+b e^{\mu K[2]}+c\right ) k \nu (m+y(x))}dK[2]+\int _1^{y(x)}\left (\frac {\exp \left (-\int _1^x-\frac {e^{\nu K[1]} k-2 m}{e^{\lambda K[1]} a+b e^{\mu K[1]}+c}dK[1]\right )}{k \nu (m+K[3])^2}-\int _1^x\left (\frac {\exp \left (-\int _1^{K[2]}-\frac {e^{\nu K[1]} k-2 m}{e^{\lambda K[1]} a+b e^{\mu K[1]}+c}dK[1]\right ) \left (e^{\nu K[2]} k-m+K[3]\right )}{\left (e^{\lambda K[2]} a+b e^{\mu K[2]}+c\right ) k \nu (m+K[3])^2}-\frac {\exp \left (-\int _1^{K[2]}-\frac {e^{\nu K[1]} k-2 m}{e^{\lambda K[1]} a+b e^{\mu K[1]}+c}dK[1]\right )}{\left (e^{\lambda K[2]} a+b e^{\mu K[2]}+c\right ) k \nu (m+K[3])}\right )dK[2]\right )dK[3]=c_1,y(x)\right ]
\]
2.3.19.4 ✗ Sympy
from sympy import *
x = symbols("x")
a = symbols("a")
b = symbols("b")
c = symbols("c")
k = symbols("k")
lambda_ = symbols("lambda_")
m = symbols("m")
mu = symbols("mu")
nu = symbols("nu")
y = Function("y")
ode = Eq(-k*m*exp(nu*x) - k*y(x)*exp(nu*x) + m**2 + (a*exp(lambda_*x) + b*exp(mu*x) + c)*Derivative(y(x), x) - y(x)**2,0)
ics = {}
dsolve(ode,func=y(x),ics=ics)
Timed Out