2.13.1 Problem 48
Internal
problem
ID
[13409]
Book
:
Handbook
of
exact
solutions
for
ordinary
differential
equations.
By
Polyanin
and
Zaitsev.
Second
edition
Section
:
Chapter
1,
section
1.2.
Riccati
Equation.
subsection
1.2.6-5.
Equations
containing
combinations
of
trigonometric
functions.
Problem
number
:
48
Date
solved
:
Sunday, January 18, 2026 at 08:00:33 PM
CAS
classification
:
[_Riccati]
2.13.1.1 Solved using first_order_ode_riccati
9.036 (sec)
Entering first order ode riccati solver
\begin{align*}
y^{\prime }&=\sin \left (\lambda x \right ) a y^{2}+b \sin \left (\lambda x \right ) \cos \left (\lambda x \right )^{n} \\
\end{align*}
In canonical form the ODE is \begin{align*} y' &= F(x,y)\\ &= \sin \left (\lambda x \right ) a y^{2}+b \sin \left (\lambda x \right ) \cos \left (\lambda x \right )^{n} \end{align*}
This is a Riccati ODE. Comparing the ODE to solve
\[
y' = \sin \left (\lambda x \right ) a y^{2}+b \sin \left (\lambda x \right ) \cos \left (\lambda x \right )^{n}
\]
With Riccati ODE standard form \[ y' = f_0(x)+ f_1(x)y+f_2(x)y^{2} \]
Shows
that \(f_0(x)=b \sin \left (\lambda x \right ) \cos \left (\lambda x \right )^{n}\), \(f_1(x)=0\) and \(f_2(x)=\sin \left (\lambda x \right ) a\). Let \begin{align*} y &= \frac {-u'}{f_2 u} \\ &= \frac {-u'}{u \sin \left (\lambda x \right ) a} \tag {1} \end{align*}
Using the above substitution in the given ODE results (after some simplification) in a second
order ODE to solve for \(u(x)\) which is
\begin{align*} f_2 u''(x) -\left ( f_2' + f_1 f_2 \right ) u'(x) + f_2^2 f_0 u(x) &= 0 \tag {2} \end{align*}
But
\begin{align*} f_2' &=\lambda \cos \left (\lambda x \right ) a\\ f_1 f_2 &=0\\ f_2^2 f_0 &=\sin \left (\lambda x \right )^{3} a^{2} b \cos \left (\lambda x \right )^{n} \end{align*}
Substituting the above terms back in equation (2) gives
\[
\sin \left (\lambda x \right ) a u^{\prime \prime }\left (x \right )-\lambda \cos \left (\lambda x \right ) a u^{\prime }\left (x \right )+\sin \left (\lambda x \right )^{3} a^{2} b \cos \left (\lambda x \right )^{n} u \left (x \right ) = 0
\]
Unable to solve. Will ask Maple to solve
this ode now.
The solution for \(u \left (x \right )\) is
\begin{equation}
\tag{3} u \left (x \right ) = c_1 \sqrt {\cos \left (\lambda x \right )}\, \operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+c_2 \sqrt {\cos \left (\lambda x \right )}\, \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )
\end{equation}
Taking derivative gives \begin{equation}
\tag{4} u^{\prime }\left (x \right ) = -\frac {c_1 \operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \lambda \sin \left (\lambda x \right )}{2 \sqrt {\cos \left (\lambda x \right )}}-\frac {2 c_1 \left (-\operatorname {BesselJ}\left (1+\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\frac {\cos \left (\lambda x \right )^{-1-\frac {n}{2}} \operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )}{2 \sqrt {\frac {a b}{\lambda ^{2}}}}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}} \left (1+\frac {n}{2}\right ) \lambda \sin \left (\lambda x \right )}{\sqrt {\cos \left (\lambda x \right )}\, \left (n +2\right )}-\frac {c_2 \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \lambda \sin \left (\lambda x \right )}{2 \sqrt {\cos \left (\lambda x \right )}}-\frac {2 c_2 \left (-\operatorname {BesselY}\left (1+\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\frac {\cos \left (\lambda x \right )^{-1-\frac {n}{2}} \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )}{2 \sqrt {\frac {a b}{\lambda ^{2}}}}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}} \left (1+\frac {n}{2}\right ) \lambda \sin \left (\lambda x \right )}{\sqrt {\cos \left (\lambda x \right )}\, \left (n +2\right )}
\end{equation}
Substituting equations (3,4) into (1) results in \begin{align*}
y &= \frac {-u'}{f_2 u} \\
y &= \frac {-u'}{u \sin \left (\lambda x \right ) a} \\
y &= -\frac {-\frac {c_1 \operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \lambda \sin \left (\lambda x \right )}{2 \sqrt {\cos \left (\lambda x \right )}}-\frac {2 c_1 \left (-\operatorname {BesselJ}\left (1+\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\frac {\cos \left (\lambda x \right )^{-1-\frac {n}{2}} \operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )}{2 \sqrt {\frac {a b}{\lambda ^{2}}}}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}} \left (1+\frac {n}{2}\right ) \lambda \sin \left (\lambda x \right )}{\sqrt {\cos \left (\lambda x \right )}\, \left (n +2\right )}-\frac {c_2 \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \lambda \sin \left (\lambda x \right )}{2 \sqrt {\cos \left (\lambda x \right )}}-\frac {2 c_2 \left (-\operatorname {BesselY}\left (1+\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\frac {\cos \left (\lambda x \right )^{-1-\frac {n}{2}} \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )}{2 \sqrt {\frac {a b}{\lambda ^{2}}}}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}} \left (1+\frac {n}{2}\right ) \lambda \sin \left (\lambda x \right )}{\sqrt {\cos \left (\lambda x \right )}\, \left (n +2\right )}}{\sin \left (\lambda x \right ) a \left (c_1 \sqrt {\cos \left (\lambda x \right )}\, \operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+c_2 \sqrt {\cos \left (\lambda x \right )}\, \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )\right )} \\
\end{align*}
Doing change of constants, the above solution becomes \[
y = -\frac {-\frac {\operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \lambda \sin \left (\lambda x \right )}{2 \sqrt {\cos \left (\lambda x \right )}}-\frac {2 \left (-\operatorname {BesselJ}\left (1+\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\frac {\cos \left (\lambda x \right )^{-1-\frac {n}{2}} \operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )}{2 \sqrt {\frac {a b}{\lambda ^{2}}}}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}} \left (1+\frac {n}{2}\right ) \lambda \sin \left (\lambda x \right )}{\sqrt {\cos \left (\lambda x \right )}\, \left (n +2\right )}-\frac {c_3 \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \lambda \sin \left (\lambda x \right )}{2 \sqrt {\cos \left (\lambda x \right )}}-\frac {2 c_3 \left (-\operatorname {BesselY}\left (1+\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\frac {\cos \left (\lambda x \right )^{-1-\frac {n}{2}} \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )}{2 \sqrt {\frac {a b}{\lambda ^{2}}}}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}} \left (1+\frac {n}{2}\right ) \lambda \sin \left (\lambda x \right )}{\sqrt {\cos \left (\lambda x \right )}\, \left (n +2\right )}}{\sin \left (\lambda x \right ) a \left (\sqrt {\cos \left (\lambda x \right )}\, \operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+c_3 \sqrt {\cos \left (\lambda x \right )}\, \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )\right )}
\]
Simplifying the above gives
\begin{align*}
y &= \frac {\left (-\operatorname {BesselY}\left (\frac {n +3}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}} c_3 -\operatorname {BesselJ}\left (\frac {n +3}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}+c_3 \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )\right ) \lambda \sec \left (\lambda x \right )}{a \left (c_3 \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )\right )} \\
\end{align*}
Summary of solutions found
\begin{align*}
y &= \frac {\left (-\operatorname {BesselY}\left (\frac {n +3}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}} c_3 -\operatorname {BesselJ}\left (\frac {n +3}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}+c_3 \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )\right ) \lambda \sec \left (\lambda x \right )}{a \left (c_3 \operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )+\operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{1+\frac {n}{2}}}{n +2}\right )\right )} \\
\end{align*}
2.13.1.2 ✓ Maple. Time used: 0.002 (sec). Leaf size: 256
ode:=diff(y(x),x) = sin(lambda*x)*a*y(x)^2+b*sin(lambda*x)*cos(lambda*x)^n;
dsolve(ode,y(x), singsol=all);
\[
y = \frac {\left (-\sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{\frac {n}{2}+1} \operatorname {BesselY}\left (\frac {n +3}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{\frac {n}{2}+1}}{n +2}\right ) c_1 -\operatorname {BesselJ}\left (\frac {n +3}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{\frac {n}{2}+1}}{n +2}\right ) \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{\frac {n}{2}+1}+\operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{\frac {n}{2}+1}}{n +2}\right ) c_1 +\operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{\frac {n}{2}+1}}{n +2}\right )\right ) \lambda \sec \left (\lambda x \right )}{a \left (\operatorname {BesselY}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{\frac {n}{2}+1}}{n +2}\right ) c_1 +\operatorname {BesselJ}\left (\frac {1}{n +2}, \frac {2 \sqrt {\frac {a b}{\lambda ^{2}}}\, \cos \left (\lambda x \right )^{\frac {n}{2}+1}}{n +2}\right )\right )}
\]
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:
trying Riccati_symmetries
trying Riccati to 2nd Order
-> Calling odsolve with the ODE, diff(diff(y(x),x),x) = lambda*cos(lambda*x)
/sin(lambda*x)*diff(y(x),x)-a*sin(lambda*x)^2*b*cos(lambda*x)^n*y(x), y(x)
*** Sublevel 2 ***
Methods for second order ODEs:
--- Trying classification methods ---
trying a symmetry of the form [xi=0, eta=F(x)]
checking if the LODE is missing y
-> Heun: Equivalence to the GHE or one of its 4 confluent cases under a \
power @ Moebius
-> trying a solution of the form r0(x) * Y + r1(x) * Y where Y = exp(int\
(r(x), dx)) * 2F1([a1, a2], [b1], f)
-> Trying changes of variables to rationalize or make the ODE simpler
trying a symmetry of the form [xi=0, eta=F(x)]
checking if the LODE is missing y
-> Trying an equivalence, under non-integer power transformations,
to LODEs admitting Liouvillian solutions.
-> Trying a Liouvillian solution using Kovacics algorithm
<- No Liouvillian solutions exists
-> Trying a solution in terms of special functions:
-> Bessel
<- Bessel successful
<- special function solution successful
Change of variables used:
[x = arccos(t)/lambda]
Linear ODE actually solved:
4*a*b*t^n*(-t^2+1)^(3/2)*u(t)+4*(-t^2+1)^(3/2)*lambda^2*diff(diff(u\
(t),t),t) = 0
<- change of variables successful
<- Riccati to 2nd Order successful
Maple step by step
\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & \frac {d}{d x}y \left (x \right )=a \sin \left (\lambda x \right ) y \left (x \right )^{2}+b \sin \left (\lambda x \right ) \cos \left (\lambda x \right )^{13409} \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & \frac {d}{d x}y \left (x \right ) \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & \frac {d}{d x}y \left (x \right )=a \sin \left (\lambda x \right ) y \left (x \right )^{2}+b \sin \left (\lambda x \right ) \cos \left (\lambda x \right )^{13409} \end {array} \]
2.13.1.3 ✓ Mathematica. Time used: 0.467 (sec). Leaf size: 695
ode=D[y[x],x]==a*Sin[\[Lambda]*x]*y[x]^2+b*Sin[\[Lambda]*x]*Cos[\[Lambda]*x]^n;
ic={};
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
\begin{align*} \text {Solution too large to show}\end{align*}
2.13.1.4 ✗ Sympy
from sympy import *
x = symbols("x")
a = symbols("a")
b = symbols("b")
lambda_ = symbols("lambda_")
n = symbols("n")
y = Function("y")
ode = Eq(-a*y(x)**2*sin(lambda_*x) - b*sin(lambda_*x)*cos(lambda_*x)**n + Derivative(y(x), x),0)
ics = {}
dsolve(ode,func=y(x),ics=ics)
NotImplementedError : The given ODE -(a*y(x)**2 + b*cos(lambda_*x)**n)*sin(lambda_*x) + Derivative(y
Python version: 3.12.3 (main, Aug 14 2025, 17:47:21) [GCC 13.3.0]
Sympy version 1.14.0
classify_ode(ode,func=y(x))
('factorable', '1st_power_series', 'lie_group')