6.34 problem 167

6.34.1 Maple step by step solution

Internal problem ID [15059]
Internal file name [OUTPUT/15060_Sunday_April_21_2024_01_21_56_PM_98789621/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: 167.
ODE order: 1.
ODE degree: 1.

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

Maple gives the following as the ode type

[[_1st_order, `_with_symmetry_[F(x),G(x)*y+H(x)]`]]

Unable to solve or complete the solution.

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

6.34.1 Maple step by step solution

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

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, y*exp(x)], [0, -exp(x)*x*y+y*ln(y)]
 

Solution by Maple

Time used: 0.016 (sec). Leaf size: 11

dsolve(diff(y(x),x)=y(x)*(exp(x)+ln(y(x))),y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 0.372 (sec). Leaf size: 15

DSolve[y'[x]==y[x]*(Exp[x]+Log[y[x]]),y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to e^{e^x (x+c_1)} \]