78.7.9 problem 2 (b)

Internal problem ID [18195]
Book : DIFFERENTIAL EQUATIONS WITH APPLICATIONS AND HISTORICAL NOTES by George F. Simmons. 3rd edition. 2017. CRC press, Boca Raton FL.
Section : Chapter 2. First order equations. Section 11 (Reduction of order). Problems at page 87
Problem number : 2 (b)
Date solved : Tuesday, January 28, 2025 at 11:37:45 AM
CAS classification : [[_2nd_order, _missing_x], [_2nd_order, _with_potential_symmetries], [_2nd_order, _reducible, _mu_xy]]

\begin{align*} y y^{\prime \prime }&=y^{2} y^{\prime }+{y^{\prime }}^{2} \end{align*}

With initial conditions

\begin{align*} y \left (0\right )&=-{\frac {1}{2}}\\ y^{\prime }\left (0\right )&=1 \end{align*}

Solution by Maple

Time used: 0.079 (sec). Leaf size: 16

dsolve([y(x)*diff(y(x),x$2)=y(x)^2*diff(y(x),x)+diff(y(x),x)^2,y(0) = -1/2, D(y)(0) = 1],y(x), singsol=all)
 
\[ y = -\frac {3}{8 \,{\mathrm e}^{\frac {3 x}{2}}-2} \]

Solution by Mathematica

Time used: 1.786 (sec). Leaf size: 20

DSolve[{y[x]*D[y[x],{x,2}]==y[x]^2*D[y[x],x]+D[y[x],x]^2,{y[0]==-1/2,Derivative[1][y][0] == 1}},y[x],x,IncludeSingularSolutions -> True]
 
\[ y(x)\to \frac {3}{2-8 e^{3 x/2}} \]