## Approximation Of Function...

Thanks to everyone who helped me with the last question. Unfortunately its a double integral, so its even more complicated than I think the program can handle. I tried to approximate the function with mtalyor

l := sqrt(1+cos(x)*cos(y)*cos(x+y));

however when I plot this function as for example:

w = mtaylor(l, [x, y], 5)

this function gets worse and worse, it gets flatter, and flatter,...

## Difficult Integral, Expansion in Two Variables, Nu...

I was trying to evaluate a difficult integral on maple analiticaly but after about 5 minutes its output is the integral itself. Something like a=a; is it timing out? How can I change this to let it run for a longer period of time? Also I doubt that there is an analytic solution, so I tried to do a numerical computation, with the assumption that (a>0), and it gave the following output:

Also the original expression that Im trying to integrate...

## Constants in pdsolve...

Hi,

I wish to declare the diffusion coefficient in the Fick's diffusion law as constant and solve numerically.How do I declare constants for a pd to use in pdsolve?I also have some constants in my boundary conditions.

is the PD and,

## Problem Evaluating Integral analytically ;...

I've been trying to evaluate another integral, like exp(-(alpha*x)^2) from 0, to infinity;

However it expresses the answer as a limit of some function(alpha), how do I get the integral to come out more exactly?

Thanks

## fraction not canceling common Factors...

I was trying to evaluate a 2-dimensional integral, but my answer contained an expression like pi/pi^2;  even trying to simplify this did not reduce the fraction properly. Why does this happen, and how can I get it to display the answer properly?

Thanks

## Rules for not Maplesoft employees

Will posted recently rules for Maplesoft employees on this site. I think, it might be a good idea to have some rules for not Maplesoft employees, too. Hopefully, they can be created collaboratively. At this time, I came to the following 5.

2. Be polite.
3. Vote up the answers to your questions if you learned something from them, even if they didn't solve the problem.
4. If you answer to somebody else's question - vote that question up - if you answering to it, you found it interesting enough to do that.
5. Don't vote anybody's posts down - that feature is reserved for Maplesoft employees (current or former) to show us what they don't like in our posts.

## PDE - who can help?...

Hi friends,
here is a paper from a book, which partiell diff equation I would like to solve with MathCAD or Mathematica or Maple. WHo can help? Thanks  a lot spending your time.  here is the PDF File with the paper

## Jet bundle with anticommuting variables (kind of.....

My question is this:

In with(DifferentialGeometry): with(JetCalculus) with(Physics):

I work with the following Jet Bundle:

DGsetup([x], [u, psi], E, 40),

where psi is declared anticommuting with Setup(anticommutativeprefix={psi}).

When I work with expressions that are differential polynomials in u with coefficients arbitrary functions of u, the EulerLagrange operator behaves correctly. The same is true if I multiply these expressions by psi or by psi_1 ...

## Plotting questions...

I am recently new to maple software, but I was wondering if someone was able to help me with the following question.

I am trying to plot a 3D graph of some function f(x,y,z), I want a contour type-graph with normal axis, and I also have a few points that I want to plot on that graph:  [x1,y1,z1], ... [xn,yn,zn]; how do I do this on a single graph?

thanks so much;