30.10 problem 869

Internal problem ID [4106]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 30
Problem number: 869.
ODE order: 1.
ODE degree: 2.

CAS Maple gives this as type [[_homogeneous, `class G`]]

\[ \boxed {x {y^{\prime }}^{2}-3 y y^{\prime }=-9 x^{2}} \]

Solution by Maple

Time used: 0.062 (sec). Leaf size: 51

dsolve(x*diff(y(x),x)^2-3*y(x)*diff(y(x),x)+9*x^2 = 0,y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 0.31 (sec). Leaf size: 79

DSolve[x (y'[x])^2-3 y[x] y'[x]+9 x^2==0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to -\frac {1}{2} e^{-\frac {3 c_1}{2}} \left (4 x^3+e^{3 c_1}\right ) y(x)\to \frac {1}{2} e^{-\frac {3 c_1}{2}} \left (4 x^3+e^{3 c_1}\right ) y(x)\to -2 x^{3/2} y(x)\to 2 x^{3/2} \end{align*}