35.2 problem Ex 2

35.2.1 Maple step by step solution

Internal problem ID [11321]
Internal file name [OUTPUT/10307_Tuesday_December_27_2022_04_06_10_AM_81835214/index.tex]

Book: An elementary treatise on differential equations by Abraham Cohen. DC heath publishers. 1906
Section: Chapter IX, Miscellaneous methods for solving equations of higher order than first. Article 59. Linear equations with particular integral known. Page 136
Problem number: Ex 2.
ODE order: 3.
ODE degree: 1.

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

Maple gives the following as the ode type

[[_3rd_order, _with_linear_symmetries]]

Unable to solve or complete the solution.

\[ \boxed {x y^{\prime \prime \prime }-y^{\prime \prime }-x y^{\prime }+y=-x^{2}+1} \] Unable to solve this ODE.

35.2.1 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & \left (\frac {d}{d x}y^{\prime \prime }\right ) x -\frac {d}{d x}y^{\prime }-x y^{\prime }+y=-x^{2}+1 \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 3 \\ {} & {} & \frac {d}{d x}y^{\prime \prime } \end {array} \]

Maple trace

`Methods for third order ODEs: 
--- Trying classification methods --- 
trying a quadrature 
trying high order exact linear fully integrable 
trying differential order: 3; linear nonhomogeneous with symmetry [0,1] 
trying high order linear exact nonhomogeneous 
trying differential order: 3; missing the dependent variable 
checking if the LODE is of Euler type 
Equation is the LCLM of -1/x*y(x)+diff(y(x),x), y(x)+diff(y(x),x), -y(x)+diff(y(x),x) 
trying differential order: 1; missing the dependent variable 
checking if the LODE is of Euler type 
<- LODE of Euler type successful 
Euler equation successful 
trying differential order: 1; missing the dependent variable 
checking if the LODE has constant coefficients 
<- constant coefficients successful 
trying differential order: 1; missing the dependent variable 
checking if the LODE has constant coefficients 
<- constant coefficients successful 
<- solving the LCLM ode successful `
 

Solution by Maple

Time used: 0.016 (sec). Leaf size: 22

dsolve(x*diff(y(x),x$3)-diff(y(x),x$2)-x*diff(y(x),x)+y(x)=1-x^2,y(x), singsol=all)
 

\[ y \left (x \right ) = x^{2}+3+c_{1} x +c_{2} {\mathrm e}^{x}+c_{3} {\mathrm e}^{-x} \]

Solution by Mathematica

Time used: 0.242 (sec). Leaf size: 28

DSolve[x*y'''[x]-y''[x]-x*y'[x]+y[x]==1-x^2,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to x^2+c_1 x-c_2 \cosh (x)+i c_3 \sinh (x)+3 \]