60.1.194 problem 197

Internal problem ID [10208]
Book : Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section : Chapter 1, linear first order
Problem number : 197
Date solved : Wednesday, March 05, 2025 at 08:42:40 AM
CAS classification : [_Bernoulli]

\begin{align*} \cos \left (x \right ) y^{\prime }-y^{4}-y \sin \left (x \right )&=0 \end{align*}

Maple. Time used: 0.046 (sec). Leaf size: 179
ode:=cos(x)*diff(y(x),x)-y(x)^4-y(x)*sin(x) = 0; 
dsolve(ode,y(x), singsol=all);
 
\begin{align*} y &= \frac {\sec \left (x \right ) \left (\cos \left (x \right )^{3} \left (-c_{1} \cos \left (x \right )^{3}+2 \cos \left (x \right )^{2} \sin \left (x \right )+\sin \left (x \right )\right )^{2}\right )^{{1}/{3}}}{c_{1} \cos \left (x \right )^{3}-2 \cos \left (x \right )^{2} \sin \left (x \right )-\sin \left (x \right )} \\ y &= \frac {\sec \left (x \right ) \left (\cos \left (x \right )^{3} \left (-c_{1} \cos \left (x \right )^{3}+2 \cos \left (x \right )^{2} \sin \left (x \right )+\sin \left (x \right )\right )^{2}\right )^{{1}/{3}} \left (1+i \sqrt {3}\right )}{-2 c_{1} \cos \left (x \right )^{3}+4 \cos \left (x \right )^{2} \sin \left (x \right )+2 \sin \left (x \right )} \\ y &= \frac {\left (i \sqrt {3}-1\right ) \sec \left (x \right ) \left (\cos \left (x \right )^{3} \left (-c_{1} \cos \left (x \right )^{3}+2 \cos \left (x \right )^{2} \sin \left (x \right )+\sin \left (x \right )\right )^{2}\right )^{{1}/{3}}}{2 c_{1} \cos \left (x \right )^{3}-4 \cos \left (x \right )^{2} \sin \left (x \right )-2 \sin \left (x \right )} \\ \end{align*}
Mathematica. Time used: 1.104 (sec). Leaf size: 109
ode=Cos[x]*D[y[x],x] - y[x]^4 - y[x]*Sin[x]==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 
\begin{align*} y(x)\to \frac {1}{\sqrt [3]{-\sin ^3(x)+c_1 \cos ^3(x)-3 \sin (x) \cos ^2(x)}} \\ y(x)\to -\frac {\sqrt [3]{-1}}{\sqrt [3]{-\sin ^3(x)+c_1 \cos ^3(x)-3 \sin (x) \cos ^2(x)}} \\ y(x)\to \frac {(-1)^{2/3}}{\sqrt [3]{-\sin ^3(x)+c_1 \cos ^3(x)-3 \sin (x) \cos ^2(x)}} \\ y(x)\to 0 \\ \end{align*}
Sympy. Time used: 7.904 (sec). Leaf size: 104
from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(-y(x)**4 - y(x)*sin(x) + cos(x)*Derivative(y(x), x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 
\[ \left [ y{\left (x \right )} = \frac {\left (-1 - \sqrt {3} i\right ) \sqrt [3]{\frac {1}{C_{1} \cos ^{3}{\left (x \right )} - 2 \sin {\left (x \right )} \cos ^{2}{\left (x \right )} - \sin {\left (x \right )}}}}{2}, \ y{\left (x \right )} = \frac {\left (-1 + \sqrt {3} i\right ) \sqrt [3]{\frac {1}{C_{1} \cos ^{3}{\left (x \right )} - 2 \sin {\left (x \right )} \cos ^{2}{\left (x \right )} - \sin {\left (x \right )}}}}{2}, \ y{\left (x \right )} = \sqrt [3]{\frac {1}{C_{1} \cos ^{3}{\left (x \right )} - 2 \sin {\left (x \right )} \cos ^{2}{\left (x \right )} - \sin {\left (x \right )}}}\right ] \]