Hi

I have managed to plot the phase portrait for the system

dx/dt = -4x(t) + y(t) + 2

dy/dt = 2x(t) - 2y(t) + 3

but i dont know how to plot the equilibrium lines

-4x + y + 2 = 0 and

2x - 2y + 3 = 0

on the same graph preferably in a different colour.

If anyone could help that would be great.

thanks

I'm trying to solve:

Hello,

I have a program where a system of DE's is solved numerically then some calculations are done to the result..

let the solution of the DE's be y(t) then we have:

A(t) = some function of y(t)

B(t) = some function of A(t)

C(t) = some function of B(t)

Those A, B and C are actually complicated formulas including sums, matrices... etc. So it's not possible to combine them in one function.

Then we'll plot C for a specific period of time.

My questions:

Hi

I'm dealing with a symmetric matrix with numerical values, very high values, e.g. 10^(50), let's call it low_index

Maple computed the inverse with

up_index:= MatrixInverse(low_index);

Let say I have a list like     L := [1, 2, 3, 4, 5, 6, 7, 8, 9, -5, -0.2];
 

Now I want to use the ListTools:-SearchAll() command and return the list index for all the

list element that are negative. I tried ListTools:-SearchAll(x < 0, K);  however that did not work.

The solution could also use a similar and simple command ....
 
 

Hi, I need to plot the curve specified by t->(t,t^3) as well as its osculating circle at several points. I know how to compute the radius of the circle but I have no idea how to get the whole thing.

I tried the following:

Alright all im really stuck on this maple question and its been bothering me for some time and i was wondering if you lot can help me out, heres the Q;

Im still getting used to maple, so forgive me for any stupid questions i may have. Thanks, David.

I have a list like     K := [A, B, C, D, E, F, G, H, I];    


Now I want to remove list element K[3], K[6] and K[8] what command do I use to do that ?  remove ?

The list is much longer so manual deletion is not an option

Hello.  I am brand new to Maple.  I would like to plot complex functions, in particular as follows:  (1) I want to show all at once all the n-roots (say 4 or 9 roots) of a complex number or a polynomial with n solutions.  (2) I would like to show the results to vectors as I perform operations.  For example, I would like to display a vector, disply another vector, and display theproduct of the two vectors, all at once.

Hi,

I'm having problems with numerical integration in maple.

I've integrals of this kind

Int(6.989220000*10^12*f^(57/50)/(1.936774504*10^19+2.094942676*10^14*f^2-9.877129764*10^14*f^(107/50)+4.636748856*10^11*f^(207/50)-1.0261950*10^7*f^(307/50)+111.*f^(407/50)), f= 10...1000)

and Maple needs ages to give me a numerical answer (with value(%) ) . Am I doing something odd or it is a "normal" computing time?

I'm running maple in a 8GB RAM, 3Ghz quad core computer

Thanks

S.V.

hello

Hello everybody,

Hello, I have a 3x3 matrix in maple and am having trouble finding the eigen vector for it.

I attached the maple file. I know this is simple stuff but i am not getting the right results when i check the eigen vectors that i get.

Your help would be much appreciated.

I ran into the following error message

system error, "bad id"

what does it mean?