H.M.mw

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## complex equation...

Hi experts,

I have an equation. I tried to use subs command to substitute x with complex number p+iq in this equation and then separate the Re and Im part of the equation, but it does not work.

How can I do this?

How can I plot the Re and Im part of the equation vs y for some different parameters?

Equation:

eq.mw

## How to arrange this equation in terms of different...

I want to arrange this equation in term of powers of x and then plot the  real and imagenery part of x vs y. How can I do this with Maple?
1-alpha*((1/x^2)+(1/(x-y)^2)+(1/(x+ay)^2))=0;

1.mw     (alpha and a are constant, for example alpha=1 and a=0.3)

## Maple returns an empty solution...

Hello. I want to organize some parameter
F=fsolve(1+x^2=j).

If j=-5, for example, an empty value 'F=' will be returned. How can I write the expression

If F=(void), then action 1, else action 2 end if

The fact is that I just don't know how to write the result (void), that is, the result of 'F ='

Thanks

## Determine whether a point with known coordinates i...

Hello

Imagine you have an irregular polygon as follows:

restart; with(plottools):with(plots):

display(polygon([[0,0],[200,0],[200,300],[250,400],[500,300],[500,500],[0,500]]),color=yellow,linestyle=solid,thickness=2);

with vertices that can be easily defined, and that you have an arbitrary point P(x,y) with coordinates of (x) and (y). I want Maple to check whether the point P(x,y) is inside or outside the polygon. In Matlab, the command (inpolygon) can be used for such a task. Is there a similar readily available command in Maple.

Thank you very much for your help and support.

## How can I get integers a, b, .. using msolve inst...

From
with(numtheory):
msolve(x^2=-1,5);                                I get
{x = 2}, {x = 3}
But I need the integers 2 and 3. Who can help me?

## How do I plot a function of two variables to show ...

Good day!

I would welcome any help to explain how to plot a simple function, z, of two variables, (x, y) so that I can show the relationships between variables.

Basically, I need to plot a family of z-curves for varying x and y values and also would like to understand how to display the z-y and z-x plots.

MaplePrimes_Nov_29.mw

## How do I solve the Error, "invalid input: rhs expe...

Hello.

I wrote some codes for solving equations in a special way. My codes work very fine when my differential system has only one equation.

But when I extend it to a system that has two or more equations, sometimes does not work and I face with error. However, in one system (2 eq) it also works. But it is only a special case. If you want, I can upload it here as well.

I am attaching the maple file containing the error. You can observe it.

By examining many cases, I think that maybe the root of the problem is that I must change my codes in a way that they are for a "system". Indeed, instead of writing codes for each differential equation, I must define a system and write these codes for a system containing some differential equations.
However, I think that the boundary conditions sometimes also may be the root of the error.

I change the attached codes for this purpose, but I failed. I prefer to not present my wrong codes for this purpose.

If it is possible, help me to change my codes.

Thanks a lot.

ERROR.mw

## Maple Code for Raifu...

I need help on maple code for solving both linear and non linear boudary condition for fractional order partial differential equation

## Maple worksheet stuck in "read-only" mode -- canno...

My Maple worksheet, which was working fine a few days ago, suddently cannot be modified. Many elements on the top bar (execute group, execute entire worksheet, insert maple prompt) are grayed out. Additionally I cannot edit any commands in the worksheet; clicking a command does not show any cursor and keyboard input does nothing.

Apparently I have entered some kind of read-only mode. I do not know how I did this. Meanwhile, if I start a new worksheet I can edit and execute as normal.

How do I revert my worksheet back to normal?

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## How to correct this error...

I don't know how overcoming this error . Thank you. MyPackage := module() export f1, f2; local loc1; option package; f1 := proc() loc1 end proc; f2 := proc( v ) loc1 := v end proc; loc1 := 2; end module: savelib('MyPackage'); Error, cannot open archive, C:\Program Files\Maple 2018\lib, for writing. restart; with(MyPackage); Error, invalid input: with expects its 1st argument, pname, to be of type {`module`, package}, but received MyPackage

## How to build a library containing my own procedure...

How to build a library (package) containing my own procedures ? Could you give me an example. Thank you.

## EDIT: within "if": f(1,1)<3.0 condition cannot be ...

Hello,

I want to create a plot of a gradient field of a function with singularities I want to draw arrows only where the function has values below 3,   or written: where f(x,y) < 3.

MY CODE:

potfeld := f(x, y) -> 1/sqrt(y^2+x^2);
for i to 5 do
for j to 3 do
if sqrt(i^2+j^2) <> 0 and sqrt((i-2)^2+j^2) <> 0 and potfeld(i, j) < 3
then P[i, j] := arrow(`<,>`(i, j), `<,>`((D[1](potfeld))(i, j), (D[2](potfeld))(i, j)))
else P[i, j] := arrow(`<,>`(i, j), `<,>`(.1, .1))
end if
end do
end do;
Pseq := seq(seq([P[k, l]], k = 1 .. 5), l = 1 .. 3);
display(Pseq, view = [1 .. 5, 1 .. 3], scaling = constrained);

RESULTS IN:
Error, cannot determine if this expression is true or false:  (1/2)*2^(1/2) < 3.0

The "(1/2)*2^(1/2)" are the value of the function potfeld(x,y) evaluated at (1,1).

I ask for your help, as with many changes and variations I have not managed to solve this issue.
+Thx and regards+

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