3.163 problem 1167

3.163.1 Solving as second order bessel ode ode

Internal problem ID [9496]
Internal file name [OUTPUT/8436_Monday_June_06_2022_03_04_14_AM_42771555/index.tex]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 2, linear second order
Problem number: 1167.
ODE order: 2.
ODE degree: 1.

The type(s) of ODE detected by this program : "second_order_bessel_ode"

Maple gives the following as the ode type

[[_2nd_order, _with_linear_symmetries]]

\[ \boxed {x^{2} y^{\prime \prime }-y^{\prime } x +\left (a \,x^{m}+b \right ) y=0} \]

3.163.1 Solving as second order bessel ode ode

Writing the ode as \begin {align*} x^{2} y^{\prime \prime }-y^{\prime } x +\left (a \,x^{m}+b \right ) y = 0\tag {1} \end {align*}

Bessel ode has the form \begin {align*} x^{2} y^{\prime \prime }+y^{\prime } x +\left (-n^{2}+x^{2}\right ) y = 0\tag {2} \end {align*}

The generalized form of Bessel ode is given by Bowman (1958) as the following \begin {align*} x^{2} y^{\prime \prime }+\left (1-2 \alpha \right ) x y^{\prime }+\left (\beta ^{2} \gamma ^{2} x^{2 \gamma }-n^{2} \gamma ^{2}+\alpha ^{2}\right ) y = 0\tag {3} \end {align*}

With the standard solution \begin {align*} y&=x^{\alpha } \left (c_{1} \operatorname {BesselJ}\left (n , \beta \,x^{\gamma }\right )+c_{2} \operatorname {BesselY}\left (n , \beta \,x^{\gamma }\right )\right )\tag {4} \end {align*}

Comparing (3) to (1) and solving for \(\alpha ,\beta ,n,\gamma \) gives \begin {align*} \alpha &= 1\\ \beta &= \frac {2 \sqrt {a}}{m}\\ n &= \frac {2 \sqrt {-b +1}}{m}\\ \gamma &= \frac {m}{2} \end {align*}

Substituting all the above into (4) gives the solution as \begin {align*} y = c_{1} x \operatorname {BesselJ}\left (\frac {2 \sqrt {-b +1}}{m}, \frac {2 \sqrt {a}\, x^{\frac {m}{2}}}{m}\right )+c_{2} x \operatorname {BesselY}\left (\frac {2 \sqrt {-b +1}}{m}, \frac {2 \sqrt {a}\, x^{\frac {m}{2}}}{m}\right ) \end {align*}

Summary

The solution(s) found are the following \begin{align*} \tag{1} y &= c_{1} x \operatorname {BesselJ}\left (\frac {2 \sqrt {-b +1}}{m}, \frac {2 \sqrt {a}\, x^{\frac {m}{2}}}{m}\right )+c_{2} x \operatorname {BesselY}\left (\frac {2 \sqrt {-b +1}}{m}, \frac {2 \sqrt {a}\, x^{\frac {m}{2}}}{m}\right ) \\ \end{align*}

Verification of solutions

\[ y = c_{1} x \operatorname {BesselJ}\left (\frac {2 \sqrt {-b +1}}{m}, \frac {2 \sqrt {a}\, x^{\frac {m}{2}}}{m}\right )+c_{2} x \operatorname {BesselY}\left (\frac {2 \sqrt {-b +1}}{m}, \frac {2 \sqrt {a}\, x^{\frac {m}{2}}}{m}\right ) \] Verified OK.

Maple trace

`Methods for second order ODEs: 
--- Trying classification methods --- 
trying a symmetry of the form [xi=0, eta=F(x)] 
checking if the LODE is missing y 
-> Trying an equivalence, under non-integer power transformations, 
   to LODEs admitting Liouvillian solutions. 
   -> Trying a Liouvillian solution using Kovacics algorithm 
   <- No Liouvillian solutions exists 
-> Trying a solution in terms of special functions: 
   -> Bessel 
   <- Bessel successful 
<- special function solution successful`
 

Solution by Maple

Time used: 0.047 (sec). Leaf size: 63

dsolve(x^2*diff(diff(y(x),x),x)-x*diff(y(x),x)+(a*x^m+b)*y(x)=0,y(x), singsol=all)
 

\[ y \left (x \right ) = x \left (c_{1} \operatorname {BesselJ}\left (\frac {2 \sqrt {1-b}}{m}, \frac {2 \sqrt {a}\, x^{\frac {m}{2}}}{m}\right )+c_{2} \operatorname {BesselY}\left (\frac {2 \sqrt {1-b}}{m}, \frac {2 \sqrt {a}\, x^{\frac {m}{2}}}{m}\right )\right ) \]

Solution by Mathematica

Time used: 0.144 (sec). Leaf size: 130

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

\[ y(x)\to m^{-2/m} a^{\frac {1}{m}} \left (x^m\right )^{\frac {1}{m}} \left (c_1 \operatorname {Gamma}\left (1-\frac {2 i \sqrt {b-1}}{m}\right ) \operatorname {BesselJ}\left (-\frac {2 i \sqrt {b-1}}{m},\frac {2 \sqrt {a} \sqrt {x^m}}{m}\right )+c_2 \operatorname {Gamma}\left (\frac {2 i \sqrt {b-1}}{m}+1\right ) \operatorname {BesselJ}\left (\frac {2 i \sqrt {b-1}}{m},\frac {2 \sqrt {a} \sqrt {x^m}}{m}\right )\right ) \]