1.4 problem Problem 1(d)

Internal problem ID [10867]

Book: APPLIED DIFFERENTIAL EQUATIONS The Primary Course by Vladimir A. Dobrushkin. CRC Press 2015
Section: Chapter 2, First Order Equations. Problems page 149
Problem number: Problem 1(d).
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

\[ \boxed {x \left ({\mathrm e}^{y}+4\right )-{\mathrm e}^{x +y} y^{\prime }=0} \]

Solution by Maple

Time used: 0.047 (sec). Leaf size: 24

dsolve(x*(exp(y(x))+4)=exp(x+y(x))*diff(y(x),x),y(x), singsol=all)
 

\[ y \left (x \right ) = \ln \left (-4+c_{1} {\mathrm e}^{-x \,{\mathrm e}^{-x}-{\mathrm e}^{-x}}\right ) \]

Solution by Mathematica

Time used: 4.201 (sec). Leaf size: 47

DSolve[x*(Exp[y[x]]+4)==Exp[x+y[x]]*y'[x],y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \log \left (-4+e^{-e^{-x} (x+1)+c_1}\right ) \\ y(x)\to \log (4)+i \pi \\ y(x)\to \log (4)+i \pi \\ \end{align*}