## Problem with Solving a PDE...

Hi Everyone,

I intend to find the invariants of a 2nd-order Tensor using the representation of the rotational group as an Infinitesimal generator. However, maple does not seem to find the correct invariants $\tr \mathbf{a}$, $\tr \mathbf{a}^2$, $\tr \mathbf{a}^3$. Maple only returns an empty set. I can't seem to figure out why that is the case.

Here is my code

 >
 >
 >
 >
 >
 (1)
 >
 (2)
 >
 (3)
 >
 >
 (4)

Any input would be appreciated!

## A bug in the Multivariate Calculus Study Guide...

I just wrote up a bug report (aka "Software Change Request") but got a "We are currently experiencing technical difficulties" error so the report is not being sent.

I will just post here about the bug in case anyone knows what it is.

I am going through the Multivariate Calculus Study Guide. I went to section 1.1, and was going through the examples. At the end of an example is a link "Next Example", but when I click this I get an error and have to go back to section 1.1 Table of Contents. Kind of annoying. Also, I notice that Maple simply crashes seemingly randomly when going through this study guide. Very annoying.

Here is a screenshot of the write-up to the bug report service that isn't working, for the record

I was wondering if this is something wrong with my Maple installation or if other people experience it too.

## Why Finance:-LatticePrice gives wrong price at 1 &...

I embed Maple code in Mobius for test questions. A simple 2-step CRR tree gives significantly different answer from the calculated by hand or by R's fOptions. Here is the piece of Mobius/Maple:

$ct = maple(" with(Finance): S0:=50; X:=50; Ty:=6./12; r:=0.07; sig:=0.3156; n:=1; dt := Ty/n; u := exp(sig*sqrt(dt)); d := 1/u; pu := (exp(r*dt) - d)/(u - d); pd := 1 - pu; BT := BinomialTree(Ty,n,S0,u,pu,d,pd); cT := ST -> max(ST -$X,0);
Ec := EuropeanOption(cT, $Ty): LatticePrice(Ec,BT,$r);
");

The answer is: 6.545478168.  Exactly the same with BlackScholesBinomialTree

The correct answer should be 6.32

In this case the solution by hand is simply e^(-0.07*05)*0.5236*\$12.50

R confirms 6.32:

CRRBinomialTreeOption(TypeFlag = "ce", S=S, X=X, Time=T, r=r, b=b, sigma=sig, n=n)@price

The error decreases with the increase of number of steps. All quantities before LatticePrice are calculated corectly. Any idea of what the reason might be?

Thanks.

## Spin sigma matrices...

Dear,

I would like to do equation of motion calculations using spin matrices.

I would like to do calculations using the  coupling.

Thanks for listening.

## Taking a 2D integral...

I'm trying to use Maple to take the following integral for positive values of a, b, c and non-negative integers i and j.

I know that for fixed values of j and k this doable — for example, for j=k=0 Mathematica gives

I'm trying the following code in Maple:

Am I doing anything wrong?

## a system of pde...

Hi dears

I have a pde system and want to get the solution of this system step by step. is there any command or bunch of commands that could help me?

(pde = partial differential equations)

## Menu bar blurry in maple 2022....

I am using maple 2022 and the menu bar on top (that has restart,execute and other icons) is very blurry.
I tried the instructions here but it did not help.
https://faq.maplesoft.com/s/article/Scaling-issues-when-using-high-resolution-monitors-on-a-Windows-machine?language=en_US

## Why this expression cannot be simplified?...

simplify(sqrt((x^2 + y^2)/x)/sqrt(x^2 + y^2)) assuming x>0, y>0

is not sqrt(1/x), why?

## Unable to getdata from a plot error "Warning, data...

Warning, data could not be converted to float Matrix

## Generating Einstein Field Equations from action?...

I am wanting to generate the field equations from a modified action.
I have looked at einstein-hilbert action - MaplePrimes which says it is doable using the functional derivatives in the physics package.

I was wondering if anyone has done it before or has a template before I start from scratch.

Thank you.

## What is the difference between Physics:-CompactDis...

Hi all,

I am working with the physics package and I want to know if there is a difference between Physics:-CompactDisplay and PDEtools:-declare ?

As well as the difference between Physics:-Simplify and simplify.

For both cases, can they be used as the same ? Are they incompatible in some case?

Thanks !

Kevin

## How to plot Nabla Discrete Mittag - Leffler Functi...

How to plot Nabla Discrete Mittag - Leffler Function in Maple?

## Failed to load the worksheet: What could be the re...

For the attached worksheet "insert contents" worked two month ago. My computer settings have not changed since.

The same happens with an empty worksheet (document mode) created with 2022.2

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/Unit_of_t.mw .

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/empty.mw .

## possible transformations...

How can we unveil all the possible transformations that reduce the number of independent variables of a given pde? I tried it by using "InvarientSolutions" which gives eight possible transformations. But under those transformations, I got only two different odes. Is there any other method/command from which we can get other possible odes of a given pde?

pde_ode.mw