## solve system with variables then plot3d...

hi

I have a linear system with varibles trying to plot 3d the solutions x, y, z

here is my code: linear_var.mw

*******************************

restart;

Omega:=10:N:=0.5:M:=sqrt(N(N+1)):

a11:=0.5*(1+2*N)+M*cos(phi):
a12:=-0.5*((1+theta)^3+(1-theta)^3):a13:=-0.5*(N+M*cos(phi))*((1+theta)^3-(1-theta)^3): a21:=M*sin(phi): a22:=(-(1+2*N)+0.5*M*cos(phi))*((1+theta)^3+(1-theta)^3): a23:=-(Omega+0.5*((1+theta)^3-(1-theta)^3)*M*sin(phi)): a31:=0.25*((1+theta)^3-(1-theta)^3): a32:=Omega: a33:=-0.5-(N+0.25)*((1+theta)^3+(1-theta)^3): b1:=-0.5*a31: b2:=0: b3:=0.25+((1+theta)^3+(1-theta)^3)/8:

slove([a11*x+a12*y+a13*z=b1,a21*x+a22*y+a23*z=b2,a31*x+a32*y+a33*z=b3[,[x,y,z]);
Error, unable to match delimiters
Typesetting:-mambiguous(Typesetting:-mambiguous(slovelparlsqba11

sdotx + a12sdoty + a13sdotzequalsb1commaa21sdotx + a22sdoty +

a23sdotzequalsb2commaa31sdotx + a32sdoty + a33sdotzequalsb3lsqb

comma(xyz)rparsemi,

Typesetting:-merror("unable to match delimiters")))

plot3d(x, theta = .1 .. 5, phi = 0 .. 2*Pi, axes = boxed);
plot3d(y, theta = .1 .. 5, phi = 0 .. 2*Pi, axes = boxed); plot3d(z, theta = .1 .. 5, phi = 0 .. 2*Pi, axes = boxed);

## Solve linear system of congruences...

I would like solving systems of congruences like the following one:

154x+69y = 0 mod 7^3

13x+716y = 0 mod 13^3

23x+3059y = 0 mod 23^3

I need the minimal non-trivial solution. I know that the solution of the system above is x=1103, y=26390.

How could I find the solution with Maple?

## Can't save Maple, nothing happens...

Hi!

I'm having problems with my maple not saving. I get no error message and no windows pop up.
The error occurred after the summer holidays in Maple 2022. I use Windows 11, everything is up to date. Have no Anti-virus programs.

I have tried the following after I discovered the error:
- To install Maple 2023
- Uninstall and delete all maple folders, then reinstall Maple 2023
- Pressed Ctrl + s
- Press "Save as..."
- Pressed on the floppy disk/save icon
- Restarted computer and updated windows

The only thing I can be allowed to do is:
- Ctrl + p
- Print to PDF/printer

Really hope you can help!

## What is the alternative for a solve block in Maple...

Dear power users, I am making the switch from Mathcad towards Maple and would like to know what is the most efficient alternative in Maple for a solve block. I have attached a work document to illustrate better my question.SolveBlockQuestion.mw Any help is highly appreciated.

## simplify expresion by redefining expression in the...

Say I have ,

sol1 := C*vout*vin/(Iout*L*k^2)

and I want to simplify this expression by replacing  with .

Then I need to simplify it further by noting that , and that , so that the answer is only in terms of , , and .

I tried `eval(sol1, vin/Iout = omega*Lm)` initially to step through the first substitution, but that just returned the same expression.

Thank you.

## Question moved as I was sending a reply...

I don't know where my last exchange with @mz6687  has been moved (not to the initial question  https://www.mapleprimes.com/questions/237066-Determinant-The-System-Hangs for what I see).
Nevertheless here is the reply I was sending to which ended with the message "Page not found".
Are_you_ok_with_that.mw

Could the one who moved the question meanwhile be so kind as to attach this reply?
TIA

## How to define constants...

If one writes Pi or Catalan, the output is Pi or Catalan, and writing evalf(Pi) or evalf(Catalan) we get approximations.

I would like to define other constants behaving in the same way. How to do it?

## How do I export maplet file into .exe file ?...

How to export Maplet file to .exe file to run independently without installing Maple software?

## how to simplify this?...

I can't figure how to simplify

V:= V1*R2/(s*C*R1*R2+R1_R2)

into

V = V1 *R2/(R1+R2)/(C*R1*R2*s/(R1+R2)+1)

with Maple

Basically, divide numerator and denominator by the s^0 coefficient.

## How do I fix this error?...

Hi,

`[Length of output exceeds limit of 1000000]`

## Obtaining the homogeneous balance principle???...

Hello, I want to get the the homogeneous balance principle for the Differential-Difference Equation with Maple. Can anyone help?

the homogeneous balance principle:The balance is made between sentences with the highest degree of nonlinearity and the highest order of the available derivative. We consider the power of terms like u^p as pM and u(q) as M + q and put them equal (pM=M+q) and get the value of M. Now, if M = 1/n (where m is an integer), then we use the transformation U= W^n, where W is a new function.

example:

## How to simplify and substitute parameters in expre...

I have a equation

((D@@2)(theta))(eta) = -(1/2)*(D(theta))(eta)*(-2*(D(phi))(eta)*beta*epsilon*lambda*D[B]+2*(D(phi))(eta)*beta*epsilon*mu*D[B]+f(eta)*sin(alpha)*beta*nu+2*(D(theta))(eta)*gamma*epsilon*D[t]-2*(D(theta))(eta)*beta*epsilon*D[t]+cos(alpha)*beta*eta*nu)/(beta*sigma)

and a parameters expression

Pr:=nu/sigma; N[b] := epsilon*D[B](mu-lambda)/sigma; N[t] := epsilon*D[t](gamma-beta)/(gamma*sigma); Le := nu/D[B]

How can I seperate common terms and substitute this parameters and got this following expression

((D@@2)(theta))(eta) = -(1/2)*Pr*(D(theta))(eta)*eta*cos(alpha)-(1/2)*Pr*(D(theta))(eta)*sin(alpha)*f(eta)-N[b]*(D(theta))(eta)*(D(phi))(eta)-N[t]*(D(theta))(eta)

## Labelling multiple solutions...

When using solve or other commands to find solutions to a problem that has more than one solution, they are returned as a list. I have observed that ordering within the list is not consistent from one run to another, and I am starting to suspect, as I try to juggle a complex cubic depending on a parameter, that the labelling can change within a single run. This is inconvenient. Any advice? Am I missing something?

## Why no custom Canvas color...

For some of the users with eye problems like me, the white canvas is burning eyes out of sockets as the monitor needs to be close up. Even turning down the intensity do not work especially since all other applications on Linux can be configured to have a dark-theme, but NOT Maple it seems.

What is the reason for this resistance from Maple Developers to just ram this white canvas down our throats verion after version.

I mean, Maple is not exactly cheap, which would have been an excuse, and is formidable intellectual software, so "ability" should not be a problem

However am I to believe that just changing the canvas color, turns out to be  a serious intellectual challenge for developers ?

Google yields such custom canvas request spanning more than a decade, but users arrive at crickets and a dead end.

Please be kind and give us a customizable canvas or any DARK theme of your choice for users with visual challenges and the lots of normal users who also want a custom canvas color or dark theme. It is overdue.

At the moment I use the cumbersome table-solution with a gray background, which helps some, but it is clunky and no alternative for long term use as the window and bars itself are still white and distracts and defeats the objective somewhat.

## pde solve Solving set of partial differential equa...

`c₁₁`, `c₁₂`, `c₁₃`, `e₃₁`, `c₆₆`, `c₄₄`, `e₁₅`, rho, `&varepsilon;₁₁`, `&varepsilon;₃₃` = constants;
`U₁` := unapply(`U₁`(t, x, y, z), x, y, z, t);
`U₂` := unapply(`U₂`(t, x, y, z), x, y, x, t);
`U₃` := unapply(`U₃`(t, x, y, z), x, y, z, t);
phi := unapply(phi(t, x, y, z), x, y, z, t);

PDE1 := `c₁₁`*Diff(`U₁`, y, y) + `c₁₂`*Diff(`U₂`, x, y) + `c₁₃`*Diff(`U₃`, x, z) + `e₃₁`*Diff(phi, x, z) + `c₆₆`*Diff(`U₂`, x, y) + `c₆₆`*Diff(`U₁`, y, y) + `c₄₄`*Diff(`U₃`, x, z) + `c₄₄`*Diff(`U₁`, z, z) + `e₁₅`*Diff(phi, x, y) = rho*Diff(`U₁`, t, t);

PDE2 := `c₆₆`*Diff(`U₂`, x, y) + `c₆₆`*Diff(`U₁`, y, x) + `c₁₂`*Diff(`U₁`, x, y) + `c₁₁`*Diff(`U₂`, y, y) + `c₁₃`*Diff(`U₃`, y, z) + `e₃₁`*Diff(phi, z, y) + `c₄₄`*Diff(`U₃`, y, z) + `c₄₄`*Diff(`U₂`, y, z) + `e₁₅`*Diff(phi, y, z) = rho*Diff(`U₂`, t, t);

PDE3 := `c₄₄`*Diff(`U₃`, x, x) + `c₄₄`*Diff(`U₁`, z, x) + `e₁₅`*Diff(phi, y, x) + `c₄₄`*Diff(`U₃`, y, y) + `c₄₄`*Diff(`U₂`, z, y) + `e₁₅`*Diff(phi, y, y) + `c₁₃`*Diff(`U₁`, x, z) + `c₁₃`*Diff(`U₂`, y, z) + `c₃₃`*Diff(`U₃`, z, z) + `e₃₃`*Diff(phi, z, z) = rho*Diff(`U₃`, t, t);

PDE4 := `e₁₅`*Diff(`U₃`, x, x) + `e₁₅`*Diff(`U₁`, y, x) - `&varepsilon;₁₁`*Diff(phi, x, x) + `e₁₅`*Diff(`U₃`, yx y) + `e₁₅`*Diff(`U₂`, z, y) - `&varepsilon;₁₁`*Diff(phi, y, y) + `e₃₁`*Diff(`U₁`, y, z) + `e₃₁`*Diff(`U₂`, y, z) + `e₃₃`*Diff(`U₃`, x, z) - `&varepsilon;₃₃`*Diff(phi, z, z) = 0;

pds := [PDE1, PDE2, PDE3, PDE4];
sol := pdsolve(pds);

i was solving the above set of pde. but it was showing the following errors,

Error, (in U₁) too many levels of recursion
Error, (in unapply) variables must be unique and of type name
Error, (in U₃) too many levels of recursion
Error, (in phi) too many levels of recursion
Error, (in pdsolve/sys/info) required an indication of the solving variables for the given system

can anyone help me?

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