9.20 problem 20

Internal problem ID [1126]

Book: Elementary differential equations with boundary value problems. William F. Trench. Brooks/Cole 2001
Section: Chapter 5 linear second order equations. Section 5.6 Reduction or order. Page 253
Problem number: 20.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _with_linear_symmetries]]

Solve \begin {gather*} \boxed {x^{2} \ln \relax (x )^{2} y^{\prime \prime }-2 x \ln \relax (x ) y^{\prime }+\left (\ln \relax (x )+2\right ) y=0} \end {gather*} Given that one solution of the ode is \begin {align*} y_1 &= \ln \relax (x ) \end {align*}

Solution by Maple

Time used: 0.016 (sec). Leaf size: 14

dsolve([x^2*(ln(x))^2*diff(y(x),x$2)-2*x*ln(x)*diff(y(x),x)+(2+ln(x))*y(x)=0,ln(x)],y(x), singsol=all)
 

\[ y \relax (x ) = \ln \relax (x ) c_{1}+c_{2} x \ln \relax (x ) \]

Solution by Mathematica

Time used: 0.014 (sec). Leaf size: 15

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

\begin{align*} y(x)\to (c_2 x+c_1) \log (x) \\ \end{align*}