## Display of variable in Equation editor-does not pu...

I am trying to display multiple integrals with the equation editor in my questions. If I use the name \$eqn, for example, it does not put that in HTML format. It may leave it: x^2 +y^3. I have tried putting my variable into HTML in the algorithm but then it will not display at all. Any suggestions? I have avoided the editor as much as possible but it is impossible with definate integrals.

## Graphing an inequality...

Maple folks, I am a Maple newbie. I am trying to figure out how to graph an inequality: x + y

## Using Maple to do difficult integrals......

Hi all, I am just playing around with Maple, with curiosity, to see how smart it is and how much can I rely on it for work... Here is a probably difficult integral, I couldn't get Maple to do it: assume(b>0, T>0, a>0, w>0); int(exp(-b*sqrt(w))/sqrt(a^2+w^2), w = T .. infinity); Is there a way to get it work? I tried a few numerical values, this integral should converge... right?

## Numeric evolution of a system of ODEs...

Hello, I have a problem with a system of ODEs. The three differential equations are as follows: diff(c(t),t) = 2*(c(t))^2 + 21/50*c(t) - 1/100*(h(t))^2 - 1/5*c(t)*h(t) - (9/2000)*h(t) + 49/4000; diff(h(t),t) = h(t)*(c(t) - 1/5*(h(t)-1)); diff(k(t),t) = 8/100*k(t) - h(t) - 1/5*k(t)*h(t); `diff(c(t),t) = 2*(c(t))^2 + 21/50*c(t) - 1/100*(h(t))^2 - 1/5*c(t)*h(t) - (9/2000)*h(t) + 49/4000;` `diff(h(t),t) = h(t)*(c(t) - 1/5*(h(t)-1));` `diff(k(t),t) = 8/100*k(t) - h(t) - 1/5*k(t)*h(t);` As t goes to infinity the three variables c(t), h(t), k(t), respectively, approach certain values -in this setting `1/50`, `11/10`, `55/3`, respectively- with the values of the derivatives converging to 0. (The point is saddle path-stable.)

## How to decide the location and type of singulariti...

Hi all, I am just curious about this problem, which has been in my mind for long time. I have seen some complex-valued functions, which are not in closed-form. For example, the complex-valued functions are defined by ODE: y'(t)=a+b*y(t)+c*(y(t))^2 + ... where the numbers in above ODE are complex-valued and the complex-valued functions are defined by functions of y(t), such as exp(y(t)), etc. Such ODEs can only be solved numerically. Sometimes even a closed-form solution is available, we would rather choose to solve it numerically because the closed-form solution often involves hyper functions and super complicated expressions.

## returned expresion from solve(eqn,c) doesn't sol...

I have the following:
```>                 /             /         2          \\
>              1  | 2    2      |/ 2    2\       2  2||
>       eqn := - +\b  + a , sqrt\\b  + a /  - 4 a  c // - c
>              2
(1/2)
1  2   1  2   1 / 4      2  2    4      2  2\
eqn := - b  + - a  + - \b  + 2 b  a  + a  - 4 a  c /      - c
2      2      2
>                          solve(eqn, c)
2    2
```

## Efficient file reading and vector/matrix assignmen...

I want to solve the following task efficiently. I need to read data from S files (in my case S = 50000). Each file has T rows of 5 floats each. Here T=1000 is a time index and 5 is the dimension of a dynamical system. From each file I want to read the j coordinate and to assign its T values to a column in a matrix X. At the end of this process I'll have an X array or matrix of dimension T x S. How can I do this efficiently? When I use 'readdata' in order to read the Tx5 matrix from a single file into a list D, this is a fast process. But assigning, naively, the j column from this matrix to my matrix X, using a for loop,

## Make a pi-chart with different dynamic values and ...

Hi, I am Er. Vishal Jain new to maple prime. I need help in developing dynamic 2D-graphs(pi-chart, conic section etc.) in .mw and respectively shade the graph.

## Entering text into the body of an edit or reply. P...

While posting an initial question is not problematic, when editing or adding a comment thereafter, one is presented with a box in which to compose that is partially concealed by content at the right of the screen, e.g., Active forum topics and Recent comments. One can continue to type behind the veil and have it display fine in the preview, but this seems anomalous. I have noted it on two different computers. Do others have this problem? Is there a way to work around this besides truncating ones sentences with early returns?

## Menu command found in the manual, but not found in...

As per instructions at the bottom of page 217 of the user manual, I wish to alter the y-axis range of a 2D plot. The instructions say to right click the plot region. Select axes and then range, however, doing so allows one to select axes, but the menu item range is nowhere to be found in the menu as described by the manual. The menu only offers the choices of normal, boxed, framed, none, properties, labels, toggle gridlines, and set gridline properties.

## No snap to feature on point probe?...

My old Mathcad 7 had a snap to function that allowed one to trace a given plot. Using the point probe on Maple does not seem to have an equivalent feature. If one wants to know a particular x y location, one must hover the point probe over the desired spot, but this is not ideal as it it very sensitive to movement. Is there a snap to feature for tracing plots? If so, how is is activated?

## Translating the Matlab code to C++ code...

Hi All, I am new to Matlab.Could you please tell me how to translate the Matlab code to c++ code i.e to convert *.m to .cpp. If there are some explicit tool please let me know. Thanks in advance, Vinay