22.3 problem 1(c)

Internal problem ID [6081]

Book: An introduction to Ordinary Differential Equations. Earl A. Coddington. Dover. NY 1961
Section: Chapter 5. Existence and uniqueness of solutions to first order equations. Page 198
Problem number: 1(c).
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

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

Solution by Maple

Time used: 0.016 (sec). Leaf size: 13

dsolve(exp(x)+(exp(y(x))*(y(x)+1))*diff(y(x),x)=0,y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 60.161 (sec). Leaf size: 14

DSolve[Exp[x]+(Exp[y[x]]*(y[x]+1))*y'[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to W\left (-e^x+c_1\right ) \]