## Collpasing Once Again...

I am trying to write a paper in which I can, for presentation purposes, collapse document blocks and have the code not shown. I am running into the problem that when I collapse some document blocks code within is not displayed but when I collpase other document blocks all that goes away is the red prompt. I can't figure out why the difference. The attached file has two document blocks which, as far as I can tell, are identical except for a few words of text. When I collpase the first block the code remains displayed, but when I collapse the second block it does not. Can anyone figure out why the difference?

## Composite plots and plotting the output from proce...

Hello, I'm wondering if it is possible to produce a composite plot in Maple. What I would like to do is: 1. Take one solution of a non-autonomous differential equation, and plot it with respect to t, call this x(t). 2. Take another solution of a similar equation, also plot it with respect to t, call this y(t). 3. Take x(t) vs. t and y(t) vs. t planes and use it to create a 3-dimensional plot containing all the points where (t,x(t))=(t,y(t)). It's difficult to describe, I hope the above is helpful. On a (hopefully) simpler note, when I solve the following: odesys := diff(x(t), t) = 2*x(t)-y(t)-x(t)^3, diff(y(t), t) = x(t)

## graphs...

hi there... im trying to plot this equation onto a graph- x-2y=4 x+2y=12 I dont knw how to put it into maple.....as maple only reads one equation at a time and not as a whole???? help please....

## Can't maple even maximize such a simple function?...

Tried to maximize a simple function f(t), failed. Converted it to different forms, still failed. Simplified the function a bit by hand and tried again, still fail. Only after some major simplification by hand and a transformation: u=s^2=(1/2-t)^2, it finally worked. I must be missing something. I thought such a simple problem should certainly be solved by maple in a flash. Can someone enlighten me please? Thanks a lot. > maximize(t^2*(1-t)^2*(1+t^2)*(1+(1-t)^2), t = 0 .. 1); / 2 2 / 2\ / 2\ \ maximize\t (1 - t) \1 + t / \1 + (1 - t) /, t = 0 .. 1/

## Converting fractures to regular numbers...

Question is easy but not for me :). How do I convert fractures into regular numbers. Thank you! Greetz Pieter

## Spider & fly Dudeney problem - a new twist...

Hi Please see Spiderflygrid2.mws A spider is on the floor of a cubical room of side 1. Its position is given. Where must the fly position itself to be as far as possible from the spider? My attempt minimizes the square of the twelve possible distances. This is m. m:=min(seq(cd[i], i=1..12)); Partial derivatives of m are found with respect to xf (the x coord of the fly) eq1:=diff(m,xf); ... & with respect to yf (the y coord of the fly) eq2:=diff(m,yf); These two equations are then solved simultaneously. solve({eq1,eq2}); Maple gives an error message - is this due to the discontinuities in the expression m? Or (more likely) a fault in my Maple code?

## operation on a function of time...

Hello - this is a novice's question: Consider the following: > E1 := a = b > E2 := b = c > eliminate({E1, E2}, {b}) [{b = c}, {a - c}] So this works. > E3 := a1(t) = b1(t) > E4 := b1(t) = c1(t) > eliminate({E3, E4}, {b1}) Error, (in eliminate/recursive) invalid subscript selector What should I do in the second set above to eliminate b1(t) and get the result a1(t) = c1(t)? Thanks.

## pdsolve with point-by-point initial condition...

I'm numerically solving, using pdsolve on Maple 9, the diffusion-recombination equation. I'm interested in the long time behavior after a very short time excitation pulse. Ideally, pdsolve would have the capability to use a small time step for the initial part followed by a larger time step later. Otherwise, I could take the result of a calculation with a short time step as an initial condition for a calculation with a long time step. If anyone knows how to do either of those things, I would be grateful. Thanks, Richard

I have Maple 10.04 running on my PC. The Maplesoft product update site says Maple 10.06 update is available. Do I have to install 10.05 update first? Or can I go from 10.04 to 10.06 directly?? Thanks in advance !

## 1d phaseportrait...

Hello everybody I need to draw a phase portrait for the one-dimensional linear independent equation(just the arrows in axe X) Help me, please!!!

## Augmenting a matrix...

> Suppose I create a matrix as follows:

> Now I want to make it a 4 x 3 matrix by adding a specific row vector on top. The approach below doesn't work.

> ## Simple question about increasing the size of a Mat...

Hi I pretty new to Maple and I have the following question. I make some calculations and out pops a number of values I am interesting. This is done several times in a loop (which I don't know the number of iterations of). Now, I would like to save these values so I can use them later on. My idea was to put everything into a matrix, and increase the size of it during runtim. I.e. initialize M for 1 to 5 do some calculations that return a and b change M so that M equals the old M with a and b added as last row end do How do I do this?