6.37 problem 170

6.37.1 Maple step by step solution

Internal problem ID [15062]
Internal file name [OUTPUT/15063_Sunday_April_21_2024_01_22_02_PM_29534322/index.tex]

Book: A book of problems in ordinary differential equations. M.L. KRASNOV, A.L. KISELYOV, G.I. MARKARENKO. MIR, MOSCOW. 1983
Section: Section 6. Linear equations of the first order. The Bernoulli equation. Exercises page 54
Problem number: 170.
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.

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

6.37.1 Maple step by step solution

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

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, exp(-x^2)*(1+cos(2*y))], [0, exp(-x^2)*cos(2*y)*x^2+exp(-x^2)*x^2-sin(2*y)]
 

Solution by Maple

Time used: 0.016 (sec). Leaf size: 19

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

\[ y \left (x \right ) = \arctan \left (\left (x^{2}+2 c_{1} \right ) {\mathrm e}^{-x^{2}}\right ) \]

Solution by Mathematica

Time used: 10.038 (sec). Leaf size: 70

DSolve[y'[x]+x*Sin[2*y[x]]==2*x*Exp[-x^2]*Cos[y[x]]^2,y[x],x,IncludeSingularSolutions -> True]
 

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