12.33 problem 352

12.33.1 Maple step by step solution

Internal problem ID [3608]
Internal file name [OUTPUT/3101_Sunday_June_05_2022_08_52_09_AM_11956308/index.tex]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 12
Problem number: 352.
ODE order: 1.
ODE degree: 1.

The type(s) of ODE detected by this program : "unknown"

Maple gives the following as the ode type

[`y=_G(x,y')`]

Unable to solve or complete the solution.

\[ \boxed {y^{\prime } x^{3}-\cos \left (y\right ) \left (\cos \left (y\right )-2 \sin \left (y\right ) x^{2}\right )=0} \] Unable to determine ODE type.

12.33.1 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & y^{\prime } x^{3}-\cos \left (y\right ) \left (\cos \left (y\right )-2 \sin \left (y\right ) x^{2}\right )=0 \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & y^{\prime } \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & y^{\prime }=\frac {\cos \left (y\right ) \left (\cos \left (y\right )-2 \sin \left (y\right ) x^{2}\right )}{x^{3}} \end {array} \]

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 inverse_Riccati 
trying an equivalence to an Abel ODE 
differential order: 1; trying a linearization to 2nd order 
--- trying a change of variables {x -> y(x), y(x) -> x} 
differential order: 1; trying a linearization to 2nd order 
trying 1st order ODE linearizable_by_differentiation 
--- Trying Lie symmetry methods, 1st order --- 
`, `-> Computing symmetries using: way = 3 
`, `-> Computing symmetries using: way = 4 
`, `-> Computing symmetries using: way = 5`[0, 1/x^2*(1+cos(2*y))]
 

Solution by Maple

Time used: 0.015 (sec). Leaf size: 15

dsolve(x^3*diff(y(x),x) = cos(y(x))*(cos(y(x))-2*x^2*sin(y(x))),y(x), singsol=all)
 

\[ y \left (x \right ) = \arctan \left (\frac {\ln \left (x \right )-c_{1}}{x^{2}}\right ) \]

Solution by Mathematica

Time used: 5.952 (sec). Leaf size: 55

DSolve[x^3 y'[x]==Cos[y[x]](Cos[y[x]]-2 x^2 Sin[y[x]]),y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \arctan \left (\frac {\log (x)+4 c_1}{x^2}\right ) \\ y(x)\to -\frac {1}{2} \pi \sqrt {\frac {1}{x^4}} x^2 \\ y(x)\to \frac {1}{2} \pi \sqrt {\frac {1}{x^4}} x^2 \\ \end{align*}