Hi, i´m trying to understand how does maplesim simulate a model with differential equatyions and on maplesim help i found this:

"Numeric Integration and Event Handling

During numeric solving (or "integration"), inequality conditions that are part of the model
are monitored and an event is triggered when one or more of these conditions change.
Whenever such an event is encountered, the numeric solver is stopped and the simulation

Hi,

I have two differential equations describing a solar sail in 2D.

One is my radial direction and one is the tangential direction.

I have plotted r(t) and theta(t) but I want r(theta) so I have assigned my two differential equations and initial conditions, have my two plots for r and theta in terms of t and then I have used the following command to plot in polar coordinates:

Hi guys,

let's say that we have an ugly, massive long expression with high power products of variables for example this:

and we want to reduce the powers of these variables using these rules:

To Whom it May Concern:

I have a 3D array, P, with dimension P:=array(1..6,1..6,1..5). I would like to extract each 2D array from the 3D array and declare them as matrices. Additionally, I would like to store the sequence of matrices is a 1D array. I tried the following, but it did not work:

P:=array(1..6,1..6,1..5):

L:= matrix(1..6,1..6):

V:=array(1..5):

for l to 5 do: for i to 6 do: for j to 6 do: L[i,j] := P[i,j,l]: od: od: V[l]:=L: od:

Thx that has been helpful, would it be possible to sub these solutions F(t) into into another equation and then plot that as well? 

The other equation is: n = 10*((1/100)*modulus(diff(F(t), t))^2+modulus(diff(F(t), t)))-1/2

but i don't know if it is possible to code for that, thanks guys when we learned maple it was a pathetic 2week course and i have been struggling.

Hi

Maple wont do anything when i try to solve: DEsolve(diff(X(x), x, x)+(1.6+4*EllipticF(x, 2)^2)*X(x))

any help would be appreciated, as i need to plot the solution but I can't solve it, also the elliptic function is was aiming for was cn^2(x,2) im not sure if this is the version that i have included and so help would be appreciated.

I'm not sure this topic has ever come up.  I cannot find a way to output strikethrough characters.  Underline and subscript will get you strikethrough characters.  Is there a way to produce strikethrough output?

Hi all, I'm hopeful someone can help you with this issue I am having in implementing a Maple procedure. I use to have a strong knowledge of the programme, but haven't used Maple in a couple of years and I appear to be more rusty than I recall, I keep hitting dead ends with multiple assignments, missing arguements and so forth, so I was hoping someone can help me smooth the edges!

The problem is as follows:

q1'' - f1(q1,q2) = - q1 / (q1^2 + q2^2) ^ (3/2)

I wrote down a covariance matrix through the following command:

 A := Matrix([[a, b], [b, c]], shape = symmetric, attributes = [positive_definite]);

and then I computed the Cholesky decomposition of this matrix using afterwards the command simplify as well

B := LUDecomposition(A, method = Cholesky)

C:=simplify(%)

What I obtained is this matrix

Matrix(2, 2, {(1, 1) = sqrt(a), (1, 2) = 0, (2, 1...

Hi I have the differential equations:

X := diff(F(t), t$2)+(10+8*sin(m*t)/(m*t))*F(t) = 0

I know that if it were X := diff(F(t), t$2)+(W)*F(t) = 0, where W was a constant, then the solution would be the standard WKB sol, but with a time varying function in front this solution is no longer valid.

I know this can be done and would like some help in plotting F(t) against t and i sholud look an oscialltig curve where when sin(mt)=0 it...

Hi,

I'm new in Maple and i've a project to do. I've to find at what time is 90% of the steady-state concentration of C achieved. And the eq is 

z'=k(1/2-z)(1/3-z), where k=0.3. 

So i had worked in Mathematica before and i know that it would look something like that in there: 

eqn1 = 0 == k (1/2 - z[t]) (1/3 - z[t])

DSolve[Evaluate[{eqn1}], z[t]].

But i have no idea how to find this 90%. I hope that someone will...

People:

I wrote a Maple 15 worksheet containing a function that calls two other functions defined earlier in the worksheet.  The main function didn't work, so I replaced one of the functions that was called, by cut-and-pasting its definition into the main function.  This is obviously inconvenient because I want to alter the function that I cut-and -pasted and whenever I do it I will have to cut-and-paste again.  It also detracts from the...

Dear all, I am new here, so I am sorry in advance if I make some mistakes. The problem here is how to transform

system of 2 differential equations 4th order to the system of 4 diff equations second order, or how to reduce system of 2 equations 4th order on two equations second order with vanishing solutions which I choose because they are big. Here is example

I'm trying to use solve to find out if a system of equalities and inequalities has any solution or not, but maple 15 seems to be giving phantom solutions.  A simple example is the following:

  solve({ a + b = 1, a > 0, b > 1, c > 0 }, {a,b,c});

It gives the output

I have a set of equations