44.4.24 problem 8 (b)

Internal problem ID [7037]
Book : A First Course in Differential Equations with Modeling Applications by Dennis G. Zill. 12 ed. Metric version. 2024. Cengage learning.
Section : Chapter 2. First order differential equations. Section 2.1 Solution curves without a solution. Exercises 2.1 at page 44
Problem number : 8 (b)
Date solved : Monday, January 27, 2025 at 02:41:56 PM
CAS classification : [_quadrature]

\begin{align*} y^{\prime }&=\frac {1}{y} \end{align*}

With initial conditions

\begin{align*} y \left (-2\right )&=-1 \end{align*}

Solution by Maple

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

dsolve([diff(y(x),x)=1/y(x),y(-2) = -1],y(x), singsol=all)
 
\[ y = -\sqrt {2 x +5} \]

Solution by Mathematica

Time used: 0.002 (sec). Leaf size: 16

DSolve[{D[y[x],x]==1/y[x],{y[-2]==-1}},y[x],x,IncludeSingularSolutions -> True]
 
\[ y(x)\to -\sqrt {2 x+5} \]