4.3 problem 4

Internal problem ID [534]

Book: Elementary differential equations and boundary value problems, 10th ed., Boyce and DiPrima
Section: Section 2.5. Page 88
Problem number: 4.
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: 0.032 (sec). Leaf size: 15

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

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

Solution by Mathematica

Time used: 0.817 (sec). Leaf size: 28

DSolve[y'[t]== -1+Exp[y[t]],y[t],t,IncludeSingularSolutions -> True]
 

\begin{align*} y(t)\to \log \left (\frac {1}{2} \left (1-\tanh \left (\frac {t+c_1}{2}\right )\right )\right ) y(t)\to 0 \end{align*}