61.9.13 problem 13

Internal problem ID [12187]
Book : Handbook of exact solutions for ordinary differential equations. By Polyanin and Zaitsev. Second edition
Section : Chapter 1, section 1.2. Riccati Equation. subsection 1.2.6-1. Equations with sine
Problem number : 13
Date solved : Tuesday, January 28, 2025 at 12:58:10 AM
CAS classification : [_Riccati]

\begin{align*} \left (a \sin \left (\lambda x \right )+b \right ) \left (y^{\prime }-y^{2}\right )-a \,\lambda ^{2} \sin \left (\lambda x \right )&=0 \end{align*}

Solution by Maple

Time used: 0.007 (sec). Leaf size: 261

dsolve((a*sin(lambda*x)+b)*(diff(y(x),x)-y(x)^2)-a*lambda^2*sin(lambda*x)=0,y(x), singsol=all)
 
\[ y = \frac {\lambda \left (-2 a \left (\cos \left (\frac {\lambda x}{2}\right )^{2}-\frac {1}{2}\right ) \left (a +b \right ) \sqrt {-a^{2}+b^{2}}\, \left (a -b \right ) b^{2} \arctan \left (\frac {b \tan \left (\frac {\lambda x}{2}\right )+a}{\sqrt {-a^{2}+b^{2}}}\right )-2 c_{1} a \left (\cos \left (\frac {\lambda x}{2}\right )^{2}-\frac {1}{2}\right ) \sqrt {-a^{2}+b^{2}}+\left (a^{2} \cos \left (\frac {\lambda x}{2}\right )^{2}-\sin \left (\frac {\lambda x}{2}\right ) a b \cos \left (\frac {\lambda x}{2}\right )-\frac {a^{2}}{2}+\frac {b^{2}}{2}\right ) \left (a +b \right )^{2} \left (a -b \right )^{2}\right )}{\sqrt {-a^{2}+b^{2}}\, \left (2 \left (\sin \left (\frac {\lambda x}{2}\right ) a \cos \left (\frac {\lambda x}{2}\right )+\frac {b}{2}\right ) \left (a +b \right ) \left (a -b \right ) b^{2} \arctan \left (\frac {b \tan \left (\frac {\lambda x}{2}\right )+a}{\sqrt {-a^{2}+b^{2}}}\right )+a \cos \left (\frac {\lambda x}{2}\right ) \left (a -b \right ) \left (a +b \right ) \left (a \sin \left (\frac {\lambda x}{2}\right )+b \cos \left (\frac {\lambda x}{2}\right )\right ) \sqrt {-a^{2}+b^{2}}+2 c_{1} \left (\sin \left (\frac {\lambda x}{2}\right ) a \cos \left (\frac {\lambda x}{2}\right )+\frac {b}{2}\right )\right )} \]

Solution by Mathematica

Time used: 11.973 (sec). Leaf size: 227

DSolve[(a*Sin[\[Lambda]*x]+b)*(D[y[x],x]-y[x]^2)-a*\[Lambda]^2*Sin[\[Lambda]*x]==0,y[x],x,IncludeSingularSolutions -> True]
 
\[ \text {Solve}\left [\int _1^x-\frac {a \sin (\lambda K[1]) \lambda ^2+b y(x)^2+a \sin (\lambda K[1]) y(x)^2}{(b+a \sin (\lambda K[1])) (a \lambda \cos (\lambda K[1])+b y(x)+a \sin (\lambda K[1]) y(x))^2}dK[1]+\int _1^{y(x)}\left (\frac {1}{(a \lambda \cos (x \lambda )+b K[2]+a K[2] \sin (x \lambda ))^2}-\int _1^x\left (\frac {2 \left (a \sin (\lambda K[1]) \lambda ^2+b K[2]^2+a K[2]^2 \sin (\lambda K[1])\right )}{(a \lambda \cos (\lambda K[1])+b K[2]+a K[2] \sin (\lambda K[1]))^3}-\frac {2 b K[2]+2 a \sin (\lambda K[1]) K[2]}{(b+a \sin (\lambda K[1])) (a \lambda \cos (\lambda K[1])+b K[2]+a K[2] \sin (\lambda K[1]))^2}\right )dK[1]\right )dK[2]=c_1,y(x)\right ] \]