Dear all

I have a box contains 3 red balls and 3 white balls, we select one ball three times and we define Z to be  the number of red balls selected. 
Since, we selected three times a ball and we count the number of red balls selcted after this experiment, we have 
Z(Omega)={0,1,2,3}

Now, How CAN I determine the sigma algebra generated by Z ( which is a random variable). 
The following code  calculate the sigma algebra generated by any subset  A subset of global set X , 
I would like to use it, to verify the descripted experiment in probability. 

sigma_algebra_random_variable.mw

thank you 

I am trying to solve the following ode in Maple. Here is the code below 

dsolve(diff(b(x), x, x, x)/2 + diff(b(x), x, x)/x + 2*diff(b(x), x)/(x^2 + 1)^2 - 4*x*b(x)/(x^2 + 1)^3 = 0)

and the output I get is the following:

b(x) = DESol({-8*x^2*_Y(x) + (4*x^3 + 4*x)*diff(_Y(x), x) + (2*x^6 + 6*x^4 + 6*x^2 + 2)*diff(_Y(x), x, x) + (x^7 + 3*x^5 + 3*x^3 + x)*diff(_Y(x), x, x, x)}, {_Y(x)})

I don't understand what the function _Y(x) means. Could someone please explain? 

Thanks in advance!  

For example for an ellipsoid with principal axes 3, 2 and 1 along the x, y and z coordinate axes respectively, with center at the origin and truncated at x equals 1.

What math will reveal its center of mass and its moment of inertia for an axis of revolution through the center of mass and parallel to the y axis?

I am trying to vopy paste a table of 10*20 from maple sheet to ms word but failed. His their any special way of copying tables from maple sheet to ms word without formating chnages?

Please, how can I find all the roots  of: (H/(Hc))^2 -(4*q^2)/Pi^2*((tan(q)- q/(1-alpha))/(tan(q)-q)) with q=(i-1)*Pi+Pi/2..i*Pi+Pi/2 for n=20.

See my attempt below:

restart:with(RootFinding):
a[1] := .1093; k[3] := 7.5*10^(-12); k[2] := 3.8*10^(-12); d := 0.2e-3; eta[1] := 0.240e-1; alpha[2] := -.1104; alpha[3] := -0.1104e-2; eta[2] := .1361; xi := 1.219*10^(-6); alpha := 1-alpha[3]^2/(a[1]*eta[1]); theta[0] := 0.5e-1;
Hc := (Pi/d)*sqrt(k[2]/xi):

H := 5.5*Hc;
lambda := a[1]/(xi*H^2);

RootFinding:-NextZero(proc (q) options operator, arrow; (H/(Hc))^2 -(4*q^2)/Pi^2*((tan(q)- q/(1-alpha))/(tan(q)-q)) end proc, 0);

for j to 9 do RootFinding:-NextZero(proc (q) options operator, arrow; H^2/Hc^2-4*q^2*(tan(q)-q/(1-alpha))/(Pi^2*(tan(q)-q)) end proc, %) end do;

Error, invalid input: RootFinding:-NextZero expects its 2nd argument, zz, to be of type numeric, but received FAIL

Hi

I wanted to know how to search a list of permutations given criteria: print the permutation(s) If the 4th element of each perm was equal to [C,Z} and the seventh was equal to [B,Y]

perm.mw

Hello, 

I have an equation in the form:

x(t)=2*a+b*t+2*t;

where a and b are the unknowns that I have to find. 

my initial conditions are x(0)=1 and x(1)=1. How can I solve this equation in maple?

Thank you very much for your help!

So all I'm trying to do is a simple sequence like seq(i^2, i=1..10, 1) but with units.  The seq function is part of the Units:-Standard and Units:-Simple packages.  I couldn't find any examples with units in the help system.  For my first attempt, I tried to create a simple sequence of values with units using what is, to me, a logical syntax.  I have included the Maple input below.  I bolded the input.

with(Units:-Standard);
[*, +, -, /, <, <=, <>, =, Im, Re, ^, abs, add, arccos, arccosh, arccot, arccoth, arccsc, arccsch, arcsec, arcsech, arcsin, 

  arcsinh, arctan, arctanh, argument, ceil, collect, combine, conjugate, cos, cosh, cot, coth, csc, csch, csgn, diff, eval, 

  evalc, evalr, exp, expand, factor, floor, frac, int, ln, log,  log10, log2, max, min, mul, normal, polar, root, round, sec, 

  sech, seq, shake, signum, simplify, sin, sinh, sqrt, surd, tan,   tanh, trunc, type, verify]

seq(ii, ii = 1.0*Unit('m') .. 10.0*Unit('m'), 1.0*Unit('m'));

Error, (in Units:-Standard:-seq) wrong number (or type) of parameters in function seq

Can anyone show me the correct syntax for this?  Is there something in the help?  I tried it in 2021 and 2022 with the same result.
 

Is it possible to read and/or convert Mapleflow sheets to Maple?

This is the first time I see such an error installing Maple on windows.

Right after the MS VS run-time installation completed (which is started by Maple installer) I got an error message saying it could not install fonts and to install them "manually".

Are there detailed instructions how is one supposed to do this? And what does this actually affect? As Maple starts ok and so far I see no issue with fonts but I have not done much with it yet other than open a worksheet and type few commands.

Looking at the folder in question, I see no instructions. Only font files. It will be good if Maplesoft could provide instructions for users on how to do that.  I do not want to do something that could end breaking the Maple installation or make things worst.

Today is one of my favorite days of the year. After months and months of hard work by a lot of people, it’s finally arrived:

It's Maple launch day!

Yes, I am very pleased to announce that Maple 2022 is here.

As we’ve done in years past, Samir and I started this release by spending many hours reviewing feedback from Maple Primes posts, support emails, sessions with staff who regularly talk with customers and who use Maple themselves, and our own direct conversations with customers. Of course a year is never enough to implement every good idea, but our goal was to identity a feature set that would appeal to, delight, and hopefully excite our customers.

Ultimately, you will be the judge, but I can tell that there are some things in Maple 2022 that I am personally very excited about. These are “quality of life” improvements that have been requested by customs and make some things in Maple that were frankly kind of annoying a lot better. The rest of this post will discuss my favorite improvements in more detail (or you can watch this video), and of course, you can get much more information about these and all the other improvements in What’s New in Maple 2022.

#1 – Did you ever find yourself jumping back and forth between your Maple document and Print Preview, again and again, as you prepare your worksheet for printing or export to PDF? It can be a pain, especially with long documents that include plots, tables, and sections. So I'm happy to announce that Maple 2022 includes a new Print Layout mode. This new layout mode lets you see the page boundaries as you edit the document, so you can adjust your content as you go. In Maple 2022, what you see on the page is what you get when you print or export to PDF. Hurray!

#2 – Are you tired of explaining to your students why the graph of tan(x) doesn’t look right in Maple?  Good news!  With Maple 2022, you won’t have to have that conversation ever again. Maple 2022's new adaptive plotting algorithm means that when you plot tan(x), 1/(1-x), floor and ceiling functions, and most other curves with discontinuities, you’ll get what you expect by default – no more vertical lines, no need to specify the discont option, and it’s still fast.

#3 – Did you ever run into a situation where zooming, panning, or resizing your plot didn’t actually give you the better view of the plot you were looking for? Now Maple recomputes and redraws when needed to give you what you wanted – a good look at your plot.

#4 – Are you a fan of the Plot Builder? If you are, I'm delighted to let you know that the Plot Builder in Maple 2022 now supports plotting multiple expressions together on the same axes. So don't hold back - use the Plot Builder to customize plots and animations of any number of 2-D and 3-D expressions plots and animations. (We also got rid of that annoying empty plot when you first open it, too.)

#5 - And, by popular demand, Maple 2022 now magnifies the text in the table of contents/search results when you magnify a help page. No more squinting to find the topic of interest. My eyes are much happier.

Those are my favorites, but there is a lot more in the release. To learn more about all the improvements in Maple 2022, visit What’s New in Maple 2022

Does anyone know how to make a command for Leibniz formula for pi?

I would preferably like to use: 1-1/3+1/5-1/7+1/9..=pi/4

I don't want to sit and write everything out, but would like to make it a command, and decide myself how many calculations I would like. I have no clue how though. Anyone have an idea for that?

restart;
with(LinearAlgebra):
a := .1093;
b[3] := -0.1104e-2;
k[1] := 3.8*10^(-12);
d := 0.2e-3;
xi := -1;
theta0 := 0.1e-3;
eta[1] := 0.240e-1;
alpha := 1-b[3]^2/(a*eta[1]);
c := b[3]*xi*alpha/(eta[1]*(4*k[1]*q^2/d^2-b[3]*xi/eta[1]));

f:= q-(1-alpha)*tan(q)- c*tan(q) ;
plot(f,q=0..4*Pi,view=[DEFAULT,-1..10]):

   
n:=3: 
q[1]:=fsolve(f,q=(0..Pi/2)): 
for i from 2 to n do
q[i]:=fsolve(f,q=(2*i-3)*Pi/2..(2*i-1)*Pi/2): ##q[n]
od:

printlevel := 2;
for i from 2 to n+1 do for j from i+1 to n do b[i, j] := int((cos(q[i]-2*q[i]*z/d)-cos(q[i]))*(cos(q[j]-2*q[j]*z/d)-cos(q[j])), z = 0 .. d); b[j, i] := b[i, j] end do end do;

for i from 2 to n do a[i, i] := int((cos(q[i]-2*q[i]*z/d)-cos(q[i]))*(cos(q[i]-2*q[i]*z/d)-cos(q[i])), z = 0 .. d) end do;

for i from 2 to n do f[i] := theta0*(int(cos(q[i]-2*q[i]*z/d)-cos(q[i]), z = 0 .. d)) end do;

## I have generated a matrix using the a[i,i] above
A := Matrix([seq([seq(a[i, j], i = 2 .. n)], j = 2 .. n)]);

b := Vector([seq(f[i], i = 2 .. n)]);
     

#Please, how do I generate an upper triangular matrix using b[i,j] above?        

I am using Maple 2021.2 on Ubuntu Linux 20.04 LTS. Sometimes the Maple after start does not show Sig in part of top Maple desktop panel. So I need to restart Maple and 2nd or 3rd start is mostly OK. After that is the situation for some time good.

See attached snapshot... Any idea what is wrong?

hallo every body 

please how i do find a real roots for this equation system 

roots.mw