## Cloud problem. ...

Why am I not able to use my MaplePrimes login credentials to login into MapleCloud?

## 2system of non coupled pde with coupled boundary c...

hi

i got a problem to solve 2 nonlinear  pde equation that are not coupled but there is 8 coupled boundary condition. i can use pdsolve in maple.anyone can help me in numerical solving of these pdes?

## parametric algebraic equation involving more than ...

Hi

I want to solve quadratic eqution involving more than 2 parameters...want to analize unique soltuions and real roots also want to plot the real and unique region on graphs ....thanx

the equation is -delta*(Q*S*alpha*b-a*alpha^2+M*c+b*delta) where alpha is the varible and rest are paramters

## How to save Maple variables from worksheet...

Hello everyone, i've a problem working with Maple because i have a really big system of equations and for everything that i have to do with them, for example, collect terms, coefficients, take a lot of time from me. The problem it is when, for example, i wait 30 minutes to take the coefficients from a equation and in the next command Maple might stop, then i have to close and start all over again... My question it is if have anyway to save my file in a way that if i close and re open i dont have to compile all again. Maybe this is pretty obvious but i really dont know how to do it, because if i close my work and open again, i have to compile everything again.

## Unable to create a custom probability distribution...

I want to use Burr distribution and hence I am creating custom probability distribution. The pdf of Burr is not piecewise. It gives error.

burrpdf := alpha*k*((x-gamma)/beta)^(alpha-1)/beta(1+((x-gamma)/beta)^alpha)^(k+1)

burr_distribution := Statistics[Distribution](PDF = (alpha > 0, beta > 0, gamma > 0, k > 0), burrpdf)

Error, (in Statistics:-Distribution) invalid input: too many and/or wrong type of arguments passed to NewDistribution;

## using @ for multiple applies...

Say I want to use multiples commands on an expression

simplify(expand(eval(expr,x=y+1)))

Now similar I could use

(simplify@expand)(expr)

but how do I do it with sth like eval which needs extra arguments

(simplify@expand@eval(x->y, x=y+1))(f)

??

## Definition of Matrix after restart changed to _rta...

I'm having sone trouble with my matricies after running restart. When creating the matrice, everything is fine and they are defined as normal. But, if I run restart and try to erdefine them, they are defined as some form of

The only way I've been able to fix this besides restarting Maple is to either add or remove the colon after the matrix, depending on wether there was one. If ther was, when I remove it the matrix is defined normally and vice versa. I'm relatively new to Maple coming from Matlab and would like to start using it more, but this matrix thing is very frustrating. I've attached a copy of the maple file. Thanks

First definition, everything is normal:

## How do i open this maple document?...

Hey MaplePrimes

I have a problem with opening some of my documents in maple. When i try to open them, a box pops up with the text "How do you want to open this file?" with the options "Maple Text, Plain Text, Maple Inputs". None of these options work (document is blank) and "Plain Text" and "Maple Inputs" causes maple to crash. Is it possible to recover the documents?

ps. when i try to upload one the documents this happens:

Maple Worksheet - Error
Failed to load the worksheet /maplenet/convert/Maple_docs_til_mat.mw .

Is is possible to tell the latex output what to do if it finds a symbol?

Suppose I have the following expression:

O3^2 + k_O3NO

The normal latex output just takes it as it is and also translates k_O3NO to k_O3NO with the underscore.

I however want it to read (latex notation in math mode)

\left[ \text{O}_3 \right]^2 + k_{\text{O}_3\text{NO}}

So is that possible without changing everything manually?

edit: Just as a remark, the output at the moment for this expression reads

{{\it O3}}^{2}+{\it k\_O3NO}

and is kinda awful if compiled in latex...

Is it also possible for maple to latex realizing where a line-break is necessary?

## how to calculate potential energy in terms of gaus...

how to calculate potential energy in terms of gauss curvature?

## Eigenvalues. Mechanical problem...

I solve a mechanical exercise but i had a problem.

I know M (mass) and K (stifness) matrices (4x4).

I want to solve the (λ2M+K)v=0  eigenvalue problem, where λ are the eigenvalues and v eigenvectors.

How can i solve this problem.  I tried with the Eigenvectors() command but it didn't give the right solution.

The Eigenvalues are okay, but the eigenvectors not

K := Matrix([[4*10^7,-1.50*10^7,2*10^7,0],[-1.50*10^7,1.50*10^7,0,1.50*10^7],[2*10^7,0,8*10^7,2*10^7],[0,1.50*10^7,2*10^7,4*10^7]]);

M:=Matrix([[121.90,99.048,-91.429,0],[99.048,594.29,0,-99.048],[-91.429,0,243.81,-91.429],[0,-99.048,-91.429,121.90]]);

w1,w2:=Eigenvectors(K,M);

Acoording with the book the right eigenvectors(shape mode) are:

[0.013 991,  0.034 233,  0.073 683,  0.090 573]
[0.035 637, 0, -0.032 213, 0]
[0 ,-0.034 233, 0, 0.090 573]
[-0.013 991, 0.034 233, -0.073 683, 0.090 573]

Thank you