MaplePrimes Questions


Is it possible to solve a differential equation, where the solution is a 8x8 matrix u(t)?

The equation to solve for, "vgl", is this one:

The values for u(0) are known:

The functions QL(t) and RL(t) are also 8x8 matrix functions. They are actually Fourier series.

Can anyone point me in a direction how to tackle this in Maple?

For completness, I add the entire Maple worksheet (, but my last line obviously doesn't work ;-)

Also all the matrices for the Fourier series are added, just for completeness: RL0.txtRL1.txtRL_1.txtstrQL0.txtstrQL1.txtstrQL2.txtstrQL_1.txtstrQL_2.txtustart.txt


Any hints appreciated a lot!


Before Maple 2020, it was possible to start up Maple from the Linux commandline with multiple files, as  in

maple   -x   ...

That started up Maple's Java interface and loaded the n worksheets in separate tabs.

That no longer seems to work in Maple 2020 — now the command exits silently when invoked with multuple files.  Why?

Aside: Loading a single file works as expected, but not multiple files.


I'm still trying to get used to the commands. How do you find the height of a cylinder and plot to a graph?

Thanks in Advance.

Example: Using a Formula


Height of a Cylinder:

ex6v := 600

ex6r := 4

ex6h := ex6v/Pi(ex6r)^2







I wanted to create a group of interactive components that, when given an eqaution in a math container of an ellepses (in the form of ((x/A)^2)+((y/B)^2)=1) would pick A and B and give back two formulas of the type



So, is there a way to extract A and B from the initial formula?

Probably a dumb question, but I don't manage to read complex numbers from a text file, not even when the text file is created by Maple itself. I've been looking around, but didn't find an answer (which must be rather a simple one, I suppose).

Why is A not a matrix with complex numbers, as is B?

Hi, I'm on Maple 2020 on Mac, and running this:

Captura-de-Pantalla-2020-05-16-a-la-s-23-14-57" />

In fact, that isn't the Chromatic number of that graph. Is not possible to color that graph with 2 colors becuase C7 (Cycle with 7 vertex) is a subgraph which is imposible to color with 2 colors. Am I doing something wrong? Can you replicate this? Is this a bug or is me?



Dear all

I want if possible to solve the inequation   f(x,y)>0 using maple

Thanks for any help


Maple formerly accepted

rule1 := forall(string(y), TD(y) = D(y)):

but now that statement prodices an error message:

Error, (in forall) expecting bound variable(s) to be a name or list of unique names

The entire value of this forall structure is that it should apply to objects of specific types, but it is not obvious how to express those types; the Help page for 'forall' is essentially useless in relation to this question. 

Hi, I am a beginner of maple and I met a problem recently.

I extracted some equations from a .txt file like below:

> read “D:/blablabla/filename”


Then I want to collect all these equations to make a list EQlist=[EQ_1,EQ_2,...] but the following code doesn't work:

> EQlist:=read “D:/blablabla/filename”

Error, invalid assignment

Could anyone tell me how to construct such EQlist?

Thank you in advance.  P.S. I can't just copy and paste because these commands are supposed to be in a loop.

Dear maple users,


How to plot this function equation "An" for x=0.0001..1,0.02 with 0..1 range.

Wating for replay.

A2 := 1.107444364; A4 := 1.124502164; ad := .5; ed := 0.1e-1; pd := 21; ld := .3;
f := unapply(3*x^2-2*x^3-1.238616691*x^2*(x-1)^2-.7382714588*x^2*(x-1)^3+.1921034396*x^2*(x-1)^4+.5253305667*x^2*(x-1)^5+.7364291997*x^2*(x-1)^6+1.032724351*x^2*(x-1)^7+.8058204155*x^2*(x-1)^8+.3290860035*x^2*(x-1)^9, x);
t := unapply(.339997432+1.547096375*x^2-2.488736512*x^3+8.154594212*x^4-15.63643668*x^5+15.85832377*x^6-8.734300202*x^7+1.959461605*x^8, x);
b1 := f(x);
b2 := diff(f(x), x);
b3 := diff(f(x), x, x);
b4 := t(x);
b5 := diff(t(x), x);
An := A4*(1+(4/3)*ad)*(b5^2+b4^2/ld^2)+4*ed*pd*(b2^2/x^2+b1^2/x^4-b1*b2/x^3)/ld;
As := seq(An, x = 0.1e-2 .. 1, 0.5e-1);
L := [seq([x, As], x = 0.1e-2 .. 1, 0.5e-1)];

plots:-display(plot(L, style = point), plot(As, x = 0.1e-2 .. 1), color = blue, linestyle = solid, labels = ["η", "f'"], thickness = 1, labeldirections = [horizontal, vertical], labelfont = ['TIMES', 'BOLDOBLIQUE', 16], size = [450, 450], axes = box);


A2 := 1.107444364:

f := unapply(3*x^2-2*x^3-1.238616691*x^2*(x-1)^2-.7382714588*x^2*(x-1)^3+.1921034396*x^2*(x-1)^4+.5253305667*x^2*(x-1)^5+.7364291997*x^2*(x-1)^6+1.032724351*x^2*(x-1)^7+.8058204155*x^2*(x-1)^8+.3290860035*x^2*(x-1)^9, x):

t := unapply(.339997432+1.547096375*x^2-2.488736512*x^3+8.154594212*x^4-15.63643668*x^5+15.85832377*x^6-8.734300202*x^7+1.959461605*x^8, x):

b1 := f(x):

b2 := diff(f(x), x):

b3 := diff(f(x), x, x):

b4 := t(x):

b5 := diff(t(x), x):

An := A4*(1+(4/3)*ad)*(b5^2+b4^2/ld^2)+4*ed*pd*(b2^2/x^2+b1^2/x^4-b1*b2/x^3)/ld:

As := seq(An, x = 0.1e-2 .. 1, 0.5e-1):

L := [seq([x, As], x = 0.1e-2 .. 1, 0.5e-1)]:



plots:-display(plot(L, style = point), plot(As, x = 0.1e-2 .. 1), color = blue, linestyle = solid, labels = ["η", "f'"], thickness = 1, labeldirections = [horizontal, vertical], labelfont = ['TIMES', 'BOLDOBLIQUE', 16], size = [450, 450], axes = box)

Error, (in plot) found points with fewer or more than 2 components






Is this a bug?



I think the way I applied it above is a bit unorthodox to Maple but maybe it is a bug.  Normally I think we use unapply in this situation. 


Okay better, but I think that first way should work no?


Hi guys,

I want to solve the matrix equation. suppose we have a matrix A 4*4 which only first array of it (1,1) is equal to n and another matrix such as S which is again 4*4 and generally, we don't know its arrays and we want A and S satisfy the following equation:


how we can find out arrays of S?







I have a .mla file, filename.mla, in a folder and typed with(filename), but Maple says "Error, invalid input: with expects its 1st argument, pname, to be of type {`module`, package}, but received convex". So how to use a  .mla file in Maple exactly?


Thanks a lot.

Years ago i used maple as in a worksheet

Nowadys there are two ways to use Maple: in document mode and worksheet mode ?

Very confusing this and it seems that the old worksheet mode has nothing to do with the document mode

Now in Maple i don't now how to use the worksheet mode anymore.
Can this worksheet mode used togehter with the document mode?

This is real troublesome exercise  to use Maple, why should i use the document mode and offers it the same functionality as in the worksheet mode ?



I am trying to isolate theta/V in this equation, but Maple will only allow me to solve for either theta or V. Is there a way to make Maple solve for the expression instead of the variable?

I have attached the Maple document below. It contains some other stuff but it is mostly this equation I am interested in. It can be found near the bottom. I hope someone can help.

Best regards

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