Dear all

I have a third order equations, I would like to know the sign of its roots, not necessary to find the roots since the equations contains some parameters. All parameters used are positives. 

roots.mw

thank you

Dear all

have a nice time. 

I have a system of nonlinear differential equation with continuous delay.  I tried to find some books that define a strategy to compute the characteristic equation but unfortunattely the most of papers or books give directly the formula without any proof. 

I tried with maple, but unfortunattely no solution up to now. 

I hope find the strategy how find the characteristic equation of the attached system.

characteristic_equation.mw

thanks 

Dear all 
For n geater or equal 2, I would like to solve to find an integrer n that such satisfy an inequality. 

I would like to see how large does n have to be for  the following ineqlaity satisfied. 
But, unfortunattely Maple return 
Warning, solutions may have been lost

restart;
epsilon:=0.001;
solve(10^n /factorial(n) <= epsilon, n);

thank you 

Dear all

I would like to expand x^m using JacobiP  ( jacobi polynomials), with the two parameter alpha  and alpha +2, I have a result in my book using alpha and alpha+1 but i would like to get a similar result using alpha and alpha+2 

Inverse_formula_jacobi_polynomials.mw

Thank you 

An example of uniform motion along a generalized coordinate using the Draghilev method. (This post was inspired by school example in one of the forums.)
The equations used in the program are very simple and, I think, do not require any special comments. DM is a procedure that implements the Draghilev method with "partial parameterization".
DM_V.mw

When K = 1, parameterization is carried out by changing the angle of rotation of the wheel. That is, uniform rolling is carried out.

For K = 4, the coordinate corresponding to the position of the slider is parametrized.

When K = 6, the slider moves with acceleration, according to a given equation. Hence, we have carried out the parameterization with respect to “time”.

With the help of such techniques, we can obtain the calculation of the kinematics of both lever mechanisms and various types of manipulators.

Dear all

I have a function F(x,t) , I would like to get the first asymptotic approximations of this function when t goes to infinity for fixed x

But maple return 

Error, (in asympt) unable to compute series

series.mw

Thank you 

Dear all

I run my code, I think evrything is well coded, but I get the following error 

invalid left hand side in assignment

Please, I need a help to solve this problem,  I haven't any idea about the origin of this error 

IOMMcode.mw

Thank you 

Dear all 

I approximate the root of a given polynomial using Newton method. 

Whem I change the output option the number of iteration change as displayed, 

Why changind only output from animation to plot, the number of iterations displayed with each figure is not the same.

NewtonQuestion.mw

thank you

Dear all

I would like to create a table that contains my ouput : iteration, eigenvalues, eigenvectors, 
My code work well, but unfortunatelly I can't display a table with the wanted output. 

cccc.mw

Thank you 

Dear All,

How to draw 3D plot from given data as follows

x:=[0.1, 0.2, 0.3, 0.4, 0.5, 0.1, 0.2, 0.3, 0.4, 0.5,0.1, 0.2, 0.3, 0.4, 0.5,0.1, 0.2, 0.3, 0.4, 0.5,0.1, 0.2, 0.3, 0.4, 0.5]
y:=[0.1, 0.1, 0.1, 0.1, 0.1, 0.2, 0.2, 0.2, 0.2, 0.2, 0.3, 0.3, 0.3, 0.3, 0.3, 0.4, 0.4, 0.4, 0.4, 0.4,0.5,0.5,0.5,0.5,0.5]
z:=[1.971284960, 1.642401616, 1.372353338,1.153620572,0.9762759982,
    1.675502483, 1.411976881, 1.190627373,1.007730234,0.8570007139, 
    1.397140245, 1.184230644, 1.003688984,0.852696223,0.7268039317,
    1.144791107, 0.9725020383,0.8257592921,0.7020549659,0.5979974836,                                                                                 0.9208492326, 0.7816302394, 0.6627749172,0.5620029444,0.4766238930]
 

Like:

Product Name: Maple 17

Deal all

I would like to approximate the largest eigenvalue of a given maxtrix and its corresponding eigenvector. 
I have a problem in step 7, how obtain the index where the maximum is located, then How I return at the end of while loop 
a table contains eigenvalues, eigenvectors and err 

PWM.mw

Thank you 

Dear all

I have a coupled system of PDEs, 
I would like to return the exact solution of the system using error integral function or complementary error function is possible

compute_integral_using_erfc_fct.mw

thank you for your help 

It seems to me that Draghilev's method can be applied quite successfully to the solution of Diophantine equations. Here is a simple example where we find two solutions at the intersection line of two ellipsoids:
  x1^2-x1*x2+x2^2+x2*x3+x3^2-961=0;
  (x1-3)^2+10*x2^2+x3^2-900=0;
Solutions: (11, -4, -26) and (10, 1, 29).
 

Based on the text of the program, it is possible to solve various examples with Diophantine equations.
3d_1.mw

Explanations.
f3 is an auxiliary equation for finding the starting point, NPar is a procedure that implements the Draghilev method, the red color of the text is the place where the integer values of the points on the integral curve are filtered.

 Can be compared with the solution of the isolve function
 

 restart:
  f1 := x1^2-x1*x2+x2^2+x2*x3+x3^2-961;
  f2 := (x1-3)^2+10*x2^2+x3^2-900;
  isolve({f1, f2})

Dear all

I construct by hand the two matrices L and U so that A= LU ( LU-factorization) 
I would like to find the number of arithmetic operations required to obtain the matrices 𝐿 and 𝑈

Number_arithmetic_operation.mw

Thank you

Dear all 
I have Sol=proc(  )
local .... ;
RES:=vector with size fixed 
for k from 1 to 100  # iteration
a:=..
if a < 0.1 then 
break;
end if ;
RES[k]:=a;
end do;
print(RES);
 end proc;

My questions:
1) How can I define the vector RES with no size fixed ( we can not at the begin fix the size of RES)
2) Then how can I plot this vector versus number of iteration  
Thank you