Hello guys, i have some matrix equations.

A^(T)*X+X*A+Q = 0 , where A,Q - matrixs, X - unknown matrix, i need to solve this.

i tried to solve this from http://www.mapleprimes.com/questions/200940-How-To-Solve-Matrix-Equation-Problem-In-Maple#answer203570 methods, but not successfully.

How can to solve this problem?

multMatrix.mw

thx.

A string is wound symmetrically around a circular rod. The string goes exactly
4 times around the rod. The circumference of the rod is 4 cm and its length is 12 cm.
Find the length of the string.
Show all your work.

(It was presented at a meeting of the European Mathematical Society in 2001,
"Reference levels in mathematics in Europe at age16").

Can you solve it? You may want to try before seing the solution.
[I sometimes train olympiad students at my university, so I like such problems].

restart;
eq:= 2/Pi*cos(t), 2/Pi*sin(t), 3/2/Pi*t; # The equations of the helix, t in 0 .. 8*Pi:
               
p:=plots[spacecurve]([eq, t=0..8*Pi],scaling=constrained,color=red, thickness=5, axes=none):
plots:-display(plottools:-cylinder([0,0,0], 2/Pi, 12, style=surface, color=yellow),
                         p, scaling=constrained,axes=none);
 

VectorCalculus:-ArcLength(<eq>, t=0..8*Pi);

                           20

Let's look at the first loop around the rod.
If we develop the corresponding 1/4 of the cylinder, it results a rectangle  whose sides are 4 and 12/4 = 3.
The diagonal is 5 (ask Pythagora why), so the length of the string is 4*5 = 20.

I updated the OSX from El Capitan 10.11 to Sierra 10.12.

After then, whenever I try to input Japanese characters, Internal Error notification appears, and it crashes.
As it is not realistic to go back to the old OS, as the time when I did back up was a little before, I wouldn't do so.
Then, I might end up torelating not using Japanese until the next version of maple appears next year.
Are the situations like this ?

I know there might not be any response as this is about inputting Japanese characters.

Best wishes.

taro

A student of mine has a problem, when trying to open a *.mw file directly from Finder, by double clicking og right-click and choose Open or Open with.  

Maple will prompt - the file does not exist.

If she uses Maple and and opening the same file thru file -> open etc. There is no problem. 

Any suggestions?

Kind regards 

Per Kirkegaard

Hello,

To summarize, I have a variable ε = order(1),  which maple has assumed is a funtion ε(x,y,z) and so when I differentiate epsilon with respect to x (or y or z) I do not get 0. I get ε_x (or ε_y, ε_z). How do I ensure maple does not assume this?

More detail of my process:

I declare functions,

I have the function I want to transform,

Now I transform the variables to the new co-ordinate system. i.e. from (x,n,q) to (s,Y,z)

Good! - Everything correct so far. 

Now I want to linearise so i introduce x=x0+ε*x1; and the same for (Y,z), 

As you can see, epsilon has derivatives, which it should not. 

How I can avoid this? 

Thanks in advance - im well and truely stumped over this.

P.s. if the images do not show, the script can be found here: 

https://www.dropbox.com/sh/34gepa60xf4droq/AAAJlUcQ_Jwkc96topPvcxtXa?dl=0 

You have three cakes, with diameters 15cm, 20cm and 25cm (same width). You want to share the cakes equally among your four customers. How do you do it?
What if you want the cakes sliced into the minimum total number of pieces?

The answer is to cut the cakes in half, but five pieces is the minimum.

What I want is a procedure for a more general case.

m cakes (different diameters) divided equally amongst n people. what is the minimum number of cuts or pieces to achieve this.

cuts.mw

Hello

I am trying to solve interactively the following DE with initial condiotion b(0)=1 and maple freezes as well as my pc.Can you help me?

Hello, 

I have a PDE system. When I use pdsolve it gets me the messege " pdsolve->Warning: System is inconsistent". Is there a way I can see which equations breaks the system down? 
For this system, it's difficult to see from ayeball where the problem is. 
Thank you! 

test.mw

Hello

Unfortunately I got stuck again when trying to work with monomials.  Consider the following set of set of monomials:

f := [theta[1]*y+theta[2]*z,theta[3]+theta[4]*x+theta[5]*y+theta[6]*z+theta[7]*x*y+theta[8]*x*z+theta[9]*y*z,theta[10]*x+theta[11]*y+theta[12]*z+theta[14]*x*y+theta[15]*x*z+theta[16]*y*z+theta[17]*x^2+theta[18]*y*y+theta[19]*z*z+theta[20]];

x, y and z are the variables and thetas are the coefficients.  The coefficients theta can be zero and I need to classify the resulting set as valid or not.   Here are some examples of not valid sets

fff:=[theta[1]*y+theta[2]*z,theta[5]*y,theta[10]*x+theta[11]*y+theta[12]*z+theta[14]*x*y+theta[15]*x*z+theta[16]*y*z+theta[17]*x^2+theta[18]*y*y+theta[19]*z*z+theta[20]];

ffff:=[theta[1]*y+theta[2]*z,theta[5],theta[10]*x+theta[11]*y+theta[12]*z+theta[14]*x*y+theta[15]*x*z+theta[16]*y*z+theta[17]*x^2+theta[18]*y*y+theta[19]*z*z+theta[20]];

fffff :=[theta[1]*y+theta[2]*z,theta[3]+theta[4]*x+theta[5]*y+theta[6]*z+theta[7]*x*y+theta[8]*x*z+theta[9]*y*z,theta[12]*z+theta[19]*z*z+theta[20]];

that is, the first coordinate of the set cannot be a function of x alone, the second coordinate cannot be a function of y alone and the third coordinate cannot be a function of z only.  

I could not figure out how to do that automatically, can you help me, please?

Many thanks.

When I use the Determinant function on a matrix with (single variable) polynomial entries with real coefficients I often get an incorrect answer. I know the answers are incorrect because they have a higher degree or a lower lowest degree than is possible given the matrix elements.

However, when I replace the coefficients in the polynomials with rational numbers or I put in the option method=minor, I get the correct answer.

The problem seems to be roundoff error. However, the important error is not simply small changes in the resulting polynomial. The important error is the presence of entirely incorrect powers of the variable and not with very small coefficients.

How does this happen and why does the help page for Determinant( ) not warn of this behavior? In particuiar, why does the help page not say that using Gaussian elimination (i.e., the default) will often give incorrect answers in such cases, but using method=minor will work? Is this behavior known? I cannot find any reference to it on the internet.

Hello all. Is there any solution for the indefinite integralBadIntegral.mw

Download BadIntegral.mw

?

Thanks

i copy maple code from notepad to maple in maple window,

there is no error

my function in the code

explicit define parameters are Local type

for example

appendto("...");

func1(aaa)

Local aaa;

but when i run cmaple to read the code text file in window 8

it return error

missing operator, syntax error

at Local aaa;

originally 

i have defined

Local aaa, ii;

for ii from 1 to nops(aaa) do

etc.

but it has error too,

then i change to one by one

Local aaa;

Local ii;

still have error at Local aaa;

if i m working in maple 13 i have to solve a non linear integral equation then what will be the steps to use the do loop.

How does one obtain all solutions from dsolve? I see an option called Allsolutions, but this seems to only apply to solve and other functions. It does not work with dsolve.

For example, maple gives one solution for the following first order non-linear ODE. But the ODE has another solution y(x)=0 as well. How does one tell Maple to return all solutions? I am interested in this when using the 'implicit' option mainly. Here is an example

restart;
num:=-(exp(x)*sin(y(x))-2*y(x)*sin(x)):
den:=(exp(x)*cos(y(x))+2*cos(x)):
eq:=diff(y(x),x)=num/den;

r0:=dsolve(eq,y(x));

But when I tried y(x)=0, it turned out to also be a solution

odetest(y(x)=0,eq);
                          0

But dsolve did not return this solution on its own along with the first one.  But on another example, Maple did well, and returned all solutions. Here is the other example

eq:=(2*x*y(x)^2+2*y(x))+(2*x^2*y(x)+2*x)*diff(y(x),x);
dsolve(eq=0,y(x),'implicit');

In the above, Maple returned the two solutions. 

Is there a correct way to tell Maple dsolve to return all solutions all the time? Why did it return both solution in the above example, but not in the first example?

I am maple newbie. Thank you.