3.36 problem 4.7 (j)

Internal problem ID [13334]

Book: Ordinary Differential Equations. An introduction to the fundamentals. Kenneth B. Howell. second edition. CRC Press. FL, USA. 2020
Section: Chapter 4. SEPARABLE FIRST ORDER EQUATIONS. Additional exercises. page 90
Problem number: 4.7 (j).
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_quadrature]

\[ \boxed {y^{\prime }-{\mathrm e}^{-y}=1} \]

Solution by Maple

Time used: 0.047 (sec). Leaf size: 11

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

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

Solution by Mathematica

Time used: 1.163 (sec). Leaf size: 32

DSolve[y'[x]==Exp[-y[x]]+1,y[x],x,IncludeSingularSolutions -> True]
 

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