3.17 problem 19

Internal problem ID [1684]

Book: Differential equations and their applications, 3rd ed., M. Braun
Section: Section 1.4. Page 24
Problem number: 19.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [[_homogeneous, `class A`], _dAlembert]

\[ \boxed {{\mathrm e}^{\frac {t}{y}} \left (y-t \right ) y^{\prime }+y \left (1+{\mathrm e}^{\frac {t}{y}}\right )=0} \]

Solution by Maple

Time used: 0.047 (sec). Leaf size: 20

dsolve(exp(t/y(t))*(y(t)-t)*diff(y(t),t)+y(t)*(1+exp(t/y(t)))=0,y(t), singsol=all)
 

\[ y \left (t \right ) = -\frac {t}{\operatorname {LambertW}\left (\frac {c_{1} t}{c_{1} t -1}\right )} \]

Solution by Mathematica

Time used: 1.532 (sec). Leaf size: 34

DSolve[Exp[t/y[t]]*(y[t]-t)*y'[t]+y[t]*(1+Exp[t/y[t]])==0,y[t],t,IncludeSingularSolutions -> True]
 

\begin{align*} y(t)\to -\frac {t}{W\left (\frac {t}{t-e^{c_1}}\right )} y(t)\to -\frac {t}{W(1)} \end{align*}