## do not get the numeric value...

hi, how to find the range in which root of Eq lies and why fsolve is not giving result>?

numeric_solution.mw

## How did you get good at maple?...

Hi, I hope this question is allowed

I wish to become well learned in maple but I find all the time, when I come across a new problem, the maple help function only takes me so far. In this community are some really helpful and bright characters which I would like to match in knowledge.

Is it possible to 'know it all' in the maple universe, or are there certain areas you're well versed in over others?

what are some of the ways you have learned to use maple effectively?

kind regards, Ben

## The for loop does not recognize alias...

In using maple 17, for a for loop, the alias command is valid outside the for loop, but entering the for loop, maple verifies that alias is not recognized.The code is as follows:
with(PDEtools):
for k from 1 to 4 do
alias(u[k]=u[k](x,y,t));
alias(a[k]=a[k](x,y,t));
od:
print(has(a[1],x));
sol:=[]:
for i from 1 to 4 do
sol:=[sol[],a[i]=rhs(isolate(a[i]+diff(a[i],x)+i=0,diff(a[i],x)))];
print(has(a[i],x));
end do;
The output is as follows: thequestionofalias
true
[a[1] = a[1] + 1]
false
[a[1] = a[1] + 1, a[2] = a[2] + 2]
false
[a[1] = a[1] + 1, a[2] = a[2] + 2, a[3] = a[3] + 3]
false
[a[1] = a[1] + 1, a[2] = a[2] + 2, a[3] = a[3] + 3, a[4] = a[4] + 4]
false
Why is it outside the loop? A [1] ... A [4] has the variable x, but either a [ I ] or a [1] has no variable X.Send the question to the Forum and see which expert can answer it. See how you can make the alias command work inside a for loop! I'd appreciate it if you could answer that!

## Stopping a computation...

Is there a way to use the Button Component to stop a maple computation? I have two long functions running on nodes via grid in my app and I want to have them stopped via special button, is it possible to do in maple?

## How to solve Matrix equation ?...

Hi everyone,

In some step of my code, I need to solve the following equation: M = Id, where, M is a square matrix of dimension n and each element of this matrix M is an expression with parameters. Id, is the identity matrix.

Could you please tell me how to solve such a matrix equation M = Id, whatever n ?

Example: i would like to solve M=Id, where M is given by:
M:=Matrix(3, 3, [[-1/3*a + b + c - 2*d, -1/4*a + 2/3*c, 1/15*a - 1/4*c + 2/3*d], [e + a - 2*c, 2/3*a, -1/4*a + 2/3*c], [f - 2*a, 0, 2/3*a]]);
Id:=IdentityMatrix(3);

Best regards

Is there

## Approximate the integral using Trapezoid, simpson'...

Using maple, approximate integral of 2/(x^2-4) from 0 to .30 by using

(a) the Trapezoidal rule: n=1, h=(b-a)/n, inegral of f(x) from a to b=(h/2)(f(x0)+f(x1))

(b) Simpson’s rule:

(c) the Midpoint rule:

## point construction problem related to a defined fu...

Hi,

I try to build a point, but a problem assigning the f function blocks me

Ideas? Thanks

ConiqueEllipseComplet.mw

## Why the solution is not shown in a complete form?...

As you can see in the code, I am trying to print the solution of the ODE using the Homotopy perturbation method for N = 10 ( f[0] till f[10]), but Maple is only printing f[0],f[1], and the rest of the terms are not printed out, what could cause this issue to take place?

```

restart;
N := 10:
F(Y) :=  add(p^i*f[i](Y), i = 0..N);
HPMEq := (1 - p)*diff(F(Y), Y \$ 4) + p*(diff(F(Y), Y \$ 4) + R*(diff(F(Y), Y \$ 3)*F(Y)- diff(F(Y), Y \$ 2)*diff(F(Y), Y \$ 1))-G*diff(F(Y), Y \$ 2));
sol:=[]:
for i from 0 to N do
sol:= [ sol[],
dsolve
( [ eval
( coeff(HPMEq, p, i) = 0,
sol
),
f[i](0) = -a,
f[i](1) = -b,
D(f[i])(0) = B * D(D(f[i]))(0),
D(f[i])(1) = -B * D(D(f[i]))(1)
]
)
];
end do:
sol;

```
Please kindly try to run this code in your Maple version and tell me if all terms are printed.

## How do I remove the negative elements from a list ...

Let us consider A=[a,-b,c, d, -a,b, -d]. Is there any command or function to remove negative element from A? For this example I want to obtain [a,b,c,d]. It is worth noting that not different "a" belong in the output list or "-a".

## Equivalent to an integral...

Dear all

I would like to obtain an equivalent to this integral when n goes to infinity

int( ((1-t^2)^n, t=0..1)

Many thanks

## Changing the variables ...

Let's consider nonlinear partial differential equations as follows:

It can be reduced into the nonlinear ordinary differential equation

by using the transformation as follows:

How to write a code for transforming the PDE to ODE by Maple?

For example; let's consider the following PDE

by using the transformation above we get the following ODE.

```restart:
with(PDEtools):
tr1:={x=mu*t + xi,u(x,t)=U(xi) };
PDE := diff(u(x,t),t) +p*u(x,t)*diff(u(x,t),x) +q* diff(u(x,t),x\$3)=0;
dchange(tr1,PDE);
```

## Help for a mathematical question related bifurcati...

```How I can obtain system (21) in the following pdf file?
In the first step several changes of variables are done to obtain the system (20),
then changes the variables again repeated in the neighborhood (w1 *, w2 *) to gain Eq 21.
I have 3 questuin:
1-The change of variables performed in the neighborhood (w1 *, w2 *)
for system (20) or for system (7) ???
2-What does it mean in the neighborhood (w1 *, w2 *)?
3- How did obtaun Eq (21)?```

[paperhub.ir]10.1016@j.neucom.2010.06.023.pdf

## Ho do I substitute special variables in a list of ...

Let us consider the following list:

A := [x[1, 1]*(a*x[1, 1] + E[1, 1]) + x[2, 1]*(a*x[1, 2] + E[1, 2]) + x[3, 1]*(a*x[1, 3] + E[1, 3]), x[1, 2]*(a*x[1, 1] + E[1, 1]) + x[2, 2]*(a*x[1, 2] + E[1, 2]) + x[3, 2]*(a*x[1, 3] + E[1, 3]), x[1, 3]*(a*x[1, 1] + E[1, 1]) + x[2, 3]*(a*x[1, 2] + E[1, 2]) + x[3, 3]*(a*x[1, 3] + E[1, 3]), x[1, 1]*(a*x[2, 1] + E[2, 1]) + x[2, 1]*(a*x[2, 2] + E[2, 2]) + x[3, 1]*(a*x[2, 3] + E[2, 3]), x[1, 2]*(a*x[2, 1] + E[2, 1]) + x[2, 2]*(a*x[2, 2] + E[2, 2]) + x[3, 2]*(a*x[2, 3] + E[2, 3]), x[1, 3]*(a*x[2, 1] + E[2, 1]) + x[2, 3]*(a*x[2, 2] + E[2, 2]) + x[3, 3]*(a*x[2, 3] + E[2, 3]), x[1, 1]*(a*x[3, 1] + E[3, 1]) + x[2, 1]*(a*x[3, 2] + E[3, 2]) + x[3, 1]*(a*x[3, 3] + E[3, 3]), x[1, 2]*(a*x[3, 1] + E[3, 1]) + x[2, 2]*(a*x[3, 2] + E[3, 2]) + x[3, 2]*(a*x[3, 3] + E[3, 3]), x[1, 3]*(a*x[3, 1] + E[3, 1]) + x[2, 3]*(a*x[3, 2] + E[3, 2]) + x[3, 3]*(a*x[3, 3] + E[3, 3])]

I want to subs E[k,k]=1 when there is "a*x[k,k]+E[k,k]" as a part of polynomial in the above list.

Thank you so much in advance