## 530 Reputation

8 years, 138 days

## @vv  Thank you,  In the syste...

Thank you,
In the system of equations A , B and C must be replaced by A(t), B(t) and C(t)
because they unknown functions

I run the same code I get
Error, (in ODEtools/ODESolStruc/info) incorrect ODESolStruc: expected 1 old dependent variable in the 2nd set of transformation equations; received: 0
code_solve_system_of_equations_vv.mw

I have 8 unknows functions, \Zeta_i(t,x,y,z), i=0,1,2,3 and A(t), B(t), C(t), \psi(t,x,y,z)

## @C_R The difference equation is the...

The difference equation is the first equation in the maple code : system defined at three different times (n+1), n and n-1

thank you

## @C_R  I think everything is well n...

I think everything is well now, in my code.

A_less_than_one.mw

In the definition of beta_1 the loop from 1 to q is correct, beta_1 is a coefficient used  in A

and everything run correctly

thanks

## @Carl Love so only one i a field, s...

so only one i a field, so can not get a homomorphism between them

## @tomleslie  This means that in gen...

This means that in geneal case, for a given x,y,z and w , we can always find n, a,b and c solution of the system

Since we have many choice of x , y, z and we so for each choice we have a solution

there are infintely many solution of the system

## but...

But Maple return a zero solution

for a fixed x=1, y=1, z=6 and w=-1 we have

n=4, a=-1, b-0, c=5

is a solution for this fixed vector defined by x,y,z and w

Big thanks

## vicinity of zero since 2< 3...

The function f is defined only in the unit ball centered at zero and outside is zero.
So, we have singularity at zero, and it is integrable in the vicinity of zero since 2< 3

## 2< 3 so function is in L1_loc...

Using polar coordinate you will integrate over the range [0,1]  the function r^(-2) r^(3-1) =1  and so integrable

In general case, f(x)=|x|^(-alpha) times indicator of unit ball, is integrable over the unit ball if alpha< dimension of space  ( in our example alpha equal 2 < 3 ), so the function is integrable

## @Zeineb  Psi(x,y), theta(x,y) conv...

Psi(x,y), theta(x,y) converge to constant constant when y goes to infinity

## @Zeineb  All my function are conti...

All my function are continuous, and the remaining are positve parameter

## Pe = is a number, you can put pe=Z...

Thank you for reading my code,

Pe is not defined as a function, Pe is a real number, we can replace Pe by Z ,

## Routh-Hurwitz 'array' good idea...

Thnak you for the idea.
Using Routh-Hurwitz 'array'  can we solve the system to get the set of values where the roots are in the left half plane.