73.12.12 problem 19.2 (f)

Internal problem ID [15285]
Book : Ordinary Differential Equations. An introduction to the fundamentals. Kenneth B. Howell. second edition. CRC Press. FL, USA. 2020
Section : Chapter 19. Arbitrary Homogeneous linear equations with constant coefficients. Additional exercises page 369
Problem number : 19.2 (f)
Date solved : Thursday, March 13, 2025 at 05:51:58 AM
CAS classification : [[_high_order, _missing_x]]

\begin{align*} y^{\prime \prime \prime \prime }+2 y^{\prime \prime \prime }+10 y^{\prime \prime }+18 y^{\prime }+9 y&=0 \end{align*}

✓ Maple. Time used: 0.004 (sec). Leaf size: 27

ode:=diff(diff(diff(diff(y(x),x),x),x),x)+2*diff(diff(diff(y(x),x),x),x)+10*diff(diff(y(x),x),x)+18*diff(y(x),x)+9*y(x) = 0; 
dsolve(ode,y(x), singsol=all);
 

\[ y = {\mathrm e}^{-x} \left (c_{2} x +c_{1} \right )+c_{3} \sin \left (3 x \right )+c_4 \cos \left (3 x \right ) \]

✓ Mathematica. Time used: 0.003 (sec). Leaf size: 38

ode=D[y[x],{x,4}]+2*D[y[x],{x,3}]+10*D[y[x],{x,2}]+18*D[y[x],x]+9*y[x]==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 

\[ y(x)\to e^{-x} \left (c_4 x+c_1 e^x \cos (3 x)+c_2 e^x \sin (3 x)+c_3\right ) \]

✓ Sympy. Time used: 0.225 (sec). Leaf size: 24

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(9*y(x) + 18*Derivative(y(x), x) + 10*Derivative(y(x), (x, 2)) + 2*Derivative(y(x), (x, 3)) + Derivative(y(x), (x, 4)),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 

\[ y{\left (x \right )} = C_{3} \sin {\left (3 x \right )} + C_{4} \cos {\left (3 x \right )} + \left (C_{1} + C_{2} x\right ) e^{- x} \]