## Forward Difference Operators in Maple...

Hi,

I'm trying to define a simple forward difference operator Δ to act on a function f(n). I have defined, in a number of ways, Δ(f(n)) = f(n+1) - f(n). This works fine but I want Maple to calculate powers of Δ. e.g Δ2 (f(n))= f(n+2) - 2f(n+1) + f(n). As it stands, Maple returns (f(n+1) - f(n))2 seemingly however I define the functions.
What am I doing wrong? Help much appreciated.

DJF

## How do I expand f(x,V(g(x))) in terms of x?...

I have a collection of functions defined either in terms of a single variable - call it r - or in terms of (r and) the other functions of r.

To be more specific, there are two free functions B(r) and N(r), a function theta defined in terms of N(r) and B(r) (and their derivatives) and r, and a free function V(theta).

Finally I have a function, call it f, written in terms of B(r) and N(r) (and their derivatives), r, and V(theta) and its derivatives with respect to both theta and r.

## How to avoid domain problem when using MatrixFunct...

In the LinearAlgebra packet, I use the command MatrixFunction to calculate a function with respect to a matrix J as follow:

> restart; with(LinearAlgebra);

> J := Matrix(3, 3, {(1, 1) = 2, (1, 2) = 1, (1, 3) = 0, (2, 1) = 0,
(2, 2) = 2, (2, 3) = 1, (3, 1) = 0, (3, 2) = 0, (3, 3) = 2});

> M := MatrixFunction(J, ln(1+x), x);

Then I got the answer:

Matrix(3, 3, {(1, 1) = ln(3), (1, 2) = 1/3, (1, 3) = -1/18, (2, 1) = 0, (2, 2) = ln(3...

## Inverse Laplace of a 3rd order function problem...

Hi guys, I'm trying to solve the following function:

>with(inttrans):

>invlaplace (15/(s3 + 6s2 + 15s + 15), s, t)

but I'm not getting a viable answer - can maple answer this?

I've also simplified the above function a bit to: H(s) = 15/[(s + 2.3222)(s2 + 3.6778s + 6.4594)] and then tried to find it's inverse laplace but still don't get an answer.

## a random force...

Using Maple for Functions of a Random Variable

How to make a query is made to F (t) at each iteration of the dsolve command?...

restart;
de:=m*diff(x(t),t\$2)+b(t)*diff(x(t),t)+k*x(t)=F(t);
a random force :
nd := Statistics:-Sample(Uniform(-100, 100)):
F:=proc(t) ;
if not type(evalf(t),'numeric') then

## Which is faster?...

Hello,

I have created a for loop in which I call often the same function let's say w(x).

Is it processed faster if I call each time the function, or if I apply the function to another variable, let's say W and call W each time?

Thanks

## need help to obtian the theta(eta) and diff(theta(...

Hi i have difficulty to obtain the function of theta(eta) and diff(theta,eta) form the matrix. Every time i have to take the values from the matrix inorder to make the function of theta(eta) and diff(theta(eta),eta) which is very difficult.

Can you please make a code in MAPLE so that i may get the direct fuction of theta(eta) and diff(theta(eta),eta)from the matrix gernerated by MAPLE.

i WILL WAIT FOR YOUR QUICK RESPONSE.

## how can i eval a function wiith a matrix?...

i would like to nknow how can i eval a function wiith a matrix?

> restart; with(ArrayTools); with(LinearAlgebra); with(MTM);
varhi := 10;
varlo := 0;
npar := 2;
popsize := 9;
par := (varhi-varlo)*RandomArray((proc (A) local i;
if A::(rtable[column]) then
seq(A(i), i = 1 .. NumElems(A)) else
args;
end if

## significant figures...

is there a maple function or does anyone have a proc that will return the number of significant figures given a number? For example, when given 0.38, the proc will return 2, or when given 2.897, the proc will return 4.

## Issues w/ the Solve Function...

I just purchased Maple16 and am working on a problem where I need to solve for variables which are imbedded in non-trivial equations. When I first began using Maple16 to solve for these symolic variables, the solve function worked; however, after about 45 min of using the solve command, on non-trivial equations, it would output nothing and the cursor would move down to the next line. A simple equation such as: f(x)^2-g(x)f(x)=s(x) it will still solve. Has anyone ever experienced...

## Why Maple can not solve this integral?!...

Hi friends
This is strange for me, but Maple could not solve the below integral. I tried with online version
of Mathematica and it solved for me. The solution is Hypergeometry function.
> f := ((1/2)*r+1/r)^(1/n);

> int(f, r);
What is the problem?

Regards!

## Function in Maple...

I used to work with Matlab and recently I've started to use Maple. In Matlab you can make a function with several commands that does some calculations and calculates one parameter and you can call that function in another function. I need to the same in Maple (i.e. define a function with several commands that calculates a parameter and use the result of that function in another function). Any suggestion?

## Four function, two interval, in one plot...

Hi! I have 4 function. I wanna plot two of them in x=-0.5..0 range; the other two in x=0..0.5 range. How can I display that four function in one plot? Thanks!

## Integral function with variable upper limit...

E := proc (phi) options operator, arrow; int(1/(1-(1-1/kappa^2)*sin(phi)^2)^(1/2), phi = 0 .. phi) end proc

E(pi/2)

Is there a way to get this function to work properly without having to simplify the integral manually ?

kappa is a constant (with a value of 12.4)