## f[a](b) (indexed function) ...

If f is a procedure e.g.  f := x -> x^2;  then f[a](b)  evaluates to f(b)  (= b^2).
Do you know where is this feature documented?
(I have used this in the past, but I need now a reference and I cannot find it).

## Working with complex numbers...

Hello. There is a complex function U11[n]. Let's say I take its derivative and want to extract the real part. That is all right. Now let's say I want to get the derivative at a point and extract the real part. I can't. Are there any solutions?

HELP.mw

## what is the reason for imaginary result?...

is the reason for Image result?

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## Creating styles...

I would like to change the color and font type on the Maple-2019 inputs and outputs, so that these formatting would be applied every time I started a new document. I tried doing this through the Styles option on the Format menu, but I could not. Can anyone help? Thank you.

## Which sorting of differential equations related wi...

Which sorting related with famous sequence

for example

sorting differential equation in a list

then access the list with famous sequence as index such as using https://oeis.org/

after access with sequence as index, use choose function to get combinations then most result are isomorphism differential ideals?

## finding order and degree of ODE in Maple...

Are there commands in Maple to find the order and degree of an ODE?  Searching help I could not find anything so far.

For an example, given

restart;
ode:=(1+diff(y(x),x)^2)^(3/2)=diff(y(x),x$2) I want the command to return 2 for the order of the ODE and degree is also 2 in this case. I looked at DEtools package and googled. I am sure Maple have build in commands to do this without me having to parse the ODE myself to find out. ## How do i substitute an array/list into an equation... Asked by: Folks, I am new to maple and looking to solve for all value of a list and return alist as the result fI := [12.5, 16, 20, 25, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1000, 1250, 1600, 2000, 2500, 3150, 4000, 5000, 6300, 8000, 10000, 12500, 16000, 20000]; x:= 23 y:= 36 Lp:= 8-10*log[10]((1+(f1/(2*x))^2.5)*(1+(y/(2.*f1))^1.7)) I am looking to solve Lp to give a result in the form: [a,b,c,d....] i.e solve for all values of f1 and return a list. Many Thanks ## Permission denied : no read access... Asked by: Last month I still can read file by read “c://Users//hello//Documents//h.m” but now it return error no read access c://Users//hello//Documents/ and in security I add the m file into readable I saw open file at c drive has many shell folders i just add m file but still the same error i unencrypted m file by window properties still the same error i save file into maple roaming directory under 12 folder , still the same error i save into maple installation directory maple 12 , still the same error ## Understanding the ratios of limits of differential... Asked by: I have a system of ODEs with parameters, p[i], and variables, x[i]. f := [ -p[1]*x[1]^2+x[2], -2*p[1]^2*x[1]^3+2*p[1]*x[1]*x[2]+x[1]+1 ]; associated with the innitial conditions: [x[1](0) = p[2], x[2](0) = p[3]]. I am interested in sets of parameters where the solution x[1](t) is the same; if [p[1],p[2],p[3]] is associated with a solution x(p,t), and [ph[1],ph[2],ph[3]] is asociated with the solution x(ph,t); then x[1](p,t)=x[1](ph,t) for all t if and only if [ph[1] = ph[1], ph[2] = p[2], ph[3] = -p[1]*p[2]^2+p[2]^2*ph[1]+p[3]] i.e. ph[1] takes any real value, ph[2] takes the same values as p[2] and ph[3] takes a value determined by the original parameter vector and ph[1]. In a previous question it was demonstrated that x[2](ph,t)/x[2](p,t) rapidly converge on p[1] as t increases for a specific parameter vector that was given in the question (see graph below) This raises the question does this limit generally hold? I have struggled to do this in maple and I am suspicious of the answer i have got i.e. limit (x[2](ph,t)/x[2](p,t),t=infinity)=+/- infinity My question is + when does a finite limit exist? + what is the finite limit? ## Calculating representations of matrix group and po... Asked by: Hello, I would like to see if MAPLE fits our needs. In order to see that I would like to consider the example which is posted in H. Iwaniec :"Introduction to the spectral theory (...)" p. 36, that is as follows: Suppose that you have a PDE as follows: This PDE has the following point symmetries: These differential operators are the representations of the following matrix algebra: 1. I would like to see the MAPLE commands, which give the algebra$v_1, v_2, v_3$2. I would like to see those commands, which give you the algebra$v_1, v_2, v_3$as a representation of$X_1, X_2, X_3$. 3. Given the algebra$v$I would like to see the commands which give you the Laplace-Beltrami operator$\Delta_{LB}=y\partial_{xx} + y\partial_{yy}\$

( P.s. sorry for the intransparent form, I do not know how to insert formulae in the comment.)

G45073

## pdsolve 2D equations with unknown parameter...

possible to solve following equation with unknown parameter omega.

parameter constant.

I see before for one dimension ode this type equation was solved.

Now for 2d equation is possible?

can consider or I can send again.

Best

2d-2

## Operations on matrices...

Dear Maple users

I have a question about performing operations on a matrix and another one about retrieving information from a matrix. I am looking for the easiest (hopefully also the shortest) way to do it:

1. Given a matrix with several rows and columns. I want to permute the rows in such a way that the entries in a specific column are ordered (either ascending or decending as wished).

2. Given a matrix with several rows and columns. I want to count how many entries in a specific column are above a certain given fixed value.

I am pretty sure some of you guys out there can do it in an elegant way. Examples will be appreciated.

Regards,

Erik

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## Cloud problem. ...

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

## How to calution a integration limit variable equat...

Hello,

I am facing a problem to calculate the variable "al" in a equation like shown below.

fe := int(sqrt(1+(-5.557990765*sin(5.557990765*x)-7.3*cos(5.557990765*x)-5.6*sinh(5.557990765*x)+7.3*cosh(5.557990765*x))^2), x = 0 .. al) = .5

Is there any method in maple to solve it even through using numeric methods.