## 530 Reputation

8 years, 102 days

## Integer solution of system...

Maple

Dear all,

I wold like to find the solution of the next system of two equations with three unknowns but we assume that the unknows are positive integers. How the following code can work. Many thanks

> restart;
> assume(J, integer, J >= 0);
> assume(A, integer, A >= 0);
> assume(T, integer, T >= 0);
> eq1 := J+10*A+50*T=500;
eq2 := J+A+T = 100;
solve( {eq1,eq2},{J,A,T});

## Reccurence relation between two operator...

Maple

Hi

Hope a nice day for all

restart;

#  *%   define the product of between two operators, and q real number
a*%b = q*b*%a+1;

# First I would like to give a simple for

a^n*%b;
# and
a*%b^n;

them deduce a general for

b^n*%a^k*%b^N*%a^K-q^(k*N-n*K)*b^N*%a^K*%b^n*%a^k;

where n, k and k greater than 1 and  n geater than k

Simplification.mw

## Integral related to Legendre polynomials...

Maple

Dear all

I need a help to compute the integral from -1 to 1 of product of derivative of legendre polynomial

> restart;
> with(orthopoly);

P(n, x); # Designe the legendre polynomial of degree n
I would like to compute

int(diff(P(n,x),x)*diff(P(m,x),x),x=-1..1) ;

In this previous formula when I put n=2 and m=3 I can get the result but in general  case i cannot,

Many thanks

## Bounded solution of ODE...

Maple

Dear all

I have the following equaion

Eq := diff(phi(x, k), x, x)+(k^2+2*sech(x))*phi(x, k) = 0;

The solution is given by

phi := (I*k-tanh(x))*exp(I*k*x)/(I*k-1);

My question : At what value of k is there a bound state and in this case can we give a simple form of the solution phi(x,k)

With best regards

## Systems of linear equations ...

Maple

Dear all;

I need your help to solve the non-square system of equation

restart;
with(LinearAlgebra);
l1 := [1, 1, 1, 0, 0, 0, 0, 0, 0];

l2 := [0, 0, 0, 1, 1, 1, 0, 0, 0];

l3 := [0, 0, 0, 0, 0, 0, 1, 1, 1];

l4 := [1, 0, 0, 1, 0, 0, 1, 0, 0];

l5 := [0, 1, 0, 0, 1, 0, 0, 1, 0];

l6 := [0, 0, 1, 0, 0, 1, 0, 0, 1];

l7 := [0, 0, 1, 0, 1, 0, 1, 0, 0];

A := Matrix([l1, l2, l3, l4, l5, l6, l7]);
# Unknown vector

m := [m1, m2, m3, m4, m5, m6, m7, m8, m9];
# Right hand side

b = [15, 15, 15, 15, 15, 15, 15];

# Let the matrix equation : A m =b

1)I need your help to compute the kernel and general solution of this matrix equation

2) can we find a solution if m_k in { 2 3 4 5 6 7 8 } and each of these number appears at least once

3) If there a solution if we consider m_k in the set {0 1 2 3 4 5 6 7 8 }  and the number used exactly one

Thank you very much for your help

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