8.21 problem 13.4 (b)

Internal problem ID [13493]

Book: Ordinary Differential Equations. An introduction to the fundamentals. Kenneth B. Howell. second edition. CRC Press. FL, USA. 2020
Section: Chapter 13. Higher order equations: Extending first order concepts. Additional exercises page 259
Problem number: 13.4 (b).
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _missing_x], _Liouville, [_2nd_order, _reducible, _mu_x_y1], [_2nd_order, _reducible, _mu_xy]]

\[ \boxed {3 y y^{\prime \prime }-2 {y^{\prime }}^{2}=0} \] With initial conditions \begin {align*} [y \left (0\right ) = 8, y^{\prime }\left (0\right ) = 6] \end {align*}

Solution by Maple

Time used: 0.125 (sec). Leaf size: 11

dsolve([3*y(x)*diff(y(x),x$2)=2*diff(y(x),x)^2,y(0) = 8, D(y)(0) = 6],y(x), singsol=all)
 

\[ y \left (x \right ) = \frac {\left (x +4\right )^{3}}{8} \]

Solution by Mathematica

Time used: 0.029 (sec). Leaf size: 14

DSolve[{3*y[x]*y''[x]==2*y'[x]^2,{y[0]==8,y'[0]==6}},y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {1}{8} (x+4)^3 \]