Hello, I have a question concerning a PDE with specific IC/BC, that describes diffusion of a species in a moderately solid thin film with a finite thickness on a solid substrate that is considered semi-infinite. The thin film has an impermeable boundary at x = -h, and the interface between the thin film and the substrate occurs at x=0.  It is possible that the species of interest may be substantially depleted from the substrate, depending on how long the experiment runs.  I am not sure that I have set up the code correctly, and am using Maple 11.

Hello,

how to simplify lhs(eq) to get rhs(eq)?

eq:=y*(sum(a[n]*y^(n-2)*n*(n-1), n = 0 .. infinity)) = (sum(a[n]*y^(n-1)*n*(n-1), n = 0 .. infinity));

is(eq);    

Regards

Jerzy

Hey,

I have an ODE:

diff(x(t),t$2)+epsilon*diff(x(t),t)+x(t)=0

where 0<epsilon<<1

is there a way to plot a phase plane of this?

or I will just have to give epsilon a really really small value to plot that?

thanks in advance

Hey

How would i go about modelling the Least Square Fitting Approach in maple?

I am concentrating on a 3x3 to a 5x5 grid rather than infinate.

the formula is

y = C  + Dt

I know the least fitting approach then goes into inversiting the matrix, or something, but i dont understand the math model which is why i want to model it in Maple.

Thanks for any help

Hello,

I have a problem with the elimination of variables from set of eq.

For example:

I tried:

How would I go about adding points and a function to the same set of axes? For example I have a set of points already plotted, and I want to plot my function, f(x)=x^2 on the same graph to compare them.

Thanks.

To Maplet Experts:
There is dearth of work  on ComboBox, a maplet element.  How does one access an item in a ComboBox.  How does one know which item in the itemlist is selected.  How does one pass selected item as an argument in a function,
I will appreciate any respond to these questions. 
Pat Velez
 

hey,

can someone give me an example of plotting a phase plane without solving the ODE

suppose i got an equation

diff(x(t),t$2)+x(t)=0

without solving it

plot a phase plane (  x dot, x )

thanks in advance

Let's say I have four variables which are assigned with the following values:

A = 10

B = 25

C = 4

D = 6

When I write A*sqrt(B)/(C+D) the Maple output is "5".

I want the output to look like

How can I achieve this?

Yes, I know that one wouldn't do this in production use, but I'm just trying to set the  mapleTA up.

My "student" users are just me at present. It seems very easy to inadvertently lock assignments.

*******************************************

I just typed an expression, such as

expand((z-6+I)*((5-I)*z+9));

on a line. On the next line, I wish to evaluate this expression at at z = 4+I, say,

without having to retype the expression. How do I do this?

%

simply returns the previous line.

I have to approx how many prime number there are between 2 to 50 000 by using  int(1/ln(t),t=2..50000);

I need to use (to approximate):

a) rectangle method

b) trapezoid method

c) simpsons method

However, I can not use the fonction like simpson(1/ln(t),t=2..50000); to solve them, I need to go with the definition and I have no idea how.

Can any1 help me?

ok so i have summed down two plot functions (P1,P2) so then i can plot them together using display, however whenever i try to use display it comes up with display({Plot(...),Plot(...)}), what do i need to do right, or what have i done wrong.

I have the following equation I need to integrate

R=int((T(x) - a ) * diff(T(x) ,x ) ,x=0..L)

T(0)=To

T(L)=a

Anyone know how to solve this???

The creation of 2D color plots is not very comprehensively supported by Maple. However, such plots may be produced by using plot3d with its 'color' option. Unfortunately, plot3d(..., color=myProc(x,y)) works only under certain conditions.  The problem seems to be that myProc(x,y) is evaluated by plot3d just one time. Thereby, unassigned variables 'x' and 'y' are given over instead of numeric values. The returned expression is then used for numerous calculations of the color by successively assigning different values to 'x' and 'y'.