1.10 problem 10

Internal problem ID [4921]

Book: Fundamentals of Differential Equations. By Nagle, Saff and Snider. 9th edition. Boston. Pearson 2018.
Section: Chapter 2, First order differential equations. Section 2.2, Separable Equations. Exercises. page 46
Problem number: 10.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

\[ \boxed {y^{\prime }-\frac {x}{y^{2} \sqrt {x +1}}=0} \]

Solution by Maple

Time used: 0.015 (sec). Leaf size: 79

dsolve(diff(y(x),x)=x/(y(x)^2*sqrt(1+x)),y(x), singsol=all)
 

\begin{align*} y \left (x \right ) &= \left (2 \sqrt {1+x}\, x -4 \sqrt {1+x}+c_{1} \right )^{\frac {1}{3}} \\ y \left (x \right ) &= -\frac {\left (\left (2 x -4\right ) \sqrt {1+x}+c_{1} \right )^{\frac {1}{3}} \left (1+i \sqrt {3}\right )}{2} \\ y \left (x \right ) &= \frac {\left (\left (2 x -4\right ) \sqrt {1+x}+c_{1} \right )^{\frac {1}{3}} \left (i \sqrt {3}-1\right )}{2} \\ \end{align*}

Solution by Mathematica

Time used: 2.119 (sec). Leaf size: 110

DSolve[y'[x]==x/(y[x]^2*Sqrt[1+x]),y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \sqrt [3]{2 \sqrt {x+1} x-4 \sqrt {x+1}+3 c_1} \\ y(x)\to -\sqrt [3]{-1} \sqrt [3]{2 \sqrt {x+1} x-4 \sqrt {x+1}+3 c_1} \\ y(x)\to (-1)^{2/3} \sqrt [3]{2 \sqrt {x+1} x-4 \sqrt {x+1}+3 c_1} \\ \end{align*}