Hello everyone,

I saw a question on a different forum related to the stability of the numerical solution of a coupled ode system. The original question was about the convergence of the far field condition (infinity) for some specific values of the different parameters involved.  For the details please see the link below

http://mathematica...

Hi,I want to compute some expressions as binomial(d-2,r)*binomial(v-d-1,r-1) and something like that. In the process, there are many such expressions but with differernt parameters. Some of them can pass successfully, but some of them will generate a mistake. That is: Error, (in gcd/LinZip) variable in input expression must be in either the evaluate or retained variables.Could you please what happened to it? Thanks.

hi i have one probleam:i want solve one pde

(1/r)*(d/dr(r*dT/dr))=(1/ß)*dT/dt

ß is cte.

T=T(r,t)

Hi,

I need help for the following. I have system of ODE as follows

 

>

Hello

 I wish to solve nonlinear PDE equation numerically  in u & v coordinate . where u=t-x, v=t+x . we note x=(v-u)/2.. 

pde := diff(u(t,x),t,t) - diff(u(t,x),x,x) + x^2*u(t,x);  

 

 We need only initial condition let f(u)=sech(u) & g(v)=sech(v). So u((i,0)=f(ih), u(0,j)=g(jh) 

we summe step size of time j =  step size of spatial i .

the stencil we use , 

There are two parts to this question:

A) Graph the function and approximate any absolute extrema on the given interval.

B) Find any critical numbers, and then use them to find any absolute extrema not located at the endpoints.

__________________________________________________________________________________________________

Both of these parts have to be done using Maple. I tried asking my teacher again if she could help me through this problem,...

Given the pencil of lines a(3x+4y-10)+b(3x-y-5)=0.Find pencil of lines is tangent to the circle x^2+y^2+2x-4y=0?

I am having problems with Maple returning corrct Answer when i use solve

 

solve([-sin(x) = cos(x), 2*Pi > x and x > 0], x, AllSolutions = true)

result is :

           { x = -1/4 - Pi + Pi _Z5 }   

but we have only 3/4 Pi and 7/4 Pi as solution, but _Z5 indicates all integers. How do i get the 2 solutions  and only those 2?

 

Kind regards 

Per Kirkegaard

I have defined my own function to implement inverse erf. I am trying to extend Maple so it recognizes basic identities. For example, I would like to Maple to simplify InverseErf(erf(x)) to x when x is real. I've used the following code in a module, but it doesn't seem to work (the evalf does work). Any suggestions?

ModuleLoad := proc()
global `evalf/InverseErf`;
global `erf/InverseErf`;
global `InverseErf/erf`;
`evalf/InverseErf` := proc(x)
local y,z;

I was trying to do some exercises on the Maplesoft site. (This site to be exact: http://www.maplesoft.com/applications/view.aspx?SID=1558&view=html ; 5.3.4. Example 4: Exercise 1:  Modify the above example so that it can be used to graph the sin

 

This is my question:

 

Given (1/6)*pi^2-(Sum(1/n^2, n = 1 .. N)) < 0.1e-2, how would would I find the smallest N such that the inequality holds?

 

I tried using solve command to no avail. Any suggestions?

Hi:

Say I have an expression like this:

a0:=I*(m*x+mp*x-omega[m]*t-omega[mp]*t);

I can factor out x,t and get an expected result:
collect(a0, [x,t]);

But how would I do it if I want to force Maple to act on the argument of exp?

a1:=exp(a0);

This doesn't work:
collect(a1, [x,t])

This will do what I want for this expression but maybe not in general:

I was doing some practice problems for Maple, when I encountered this problem:

 

My code is

 

w:=x+2+sin(x+2);

subs(x+2=u,w);

 

The output however did not change both `x+2`'s into `u`.

 

The output was: x+2+sin(u)

 

Any ideas as to why? Thanks in advance.

we were given three questions to do, i got the other two ones out grand but ive been trying to do this for hours and i still don't get it.   it is 

Write a function that produces the power set of a given nite set M, i.e. the set of all subsets.

Thusyour function has

Argument: a finite set M,

Returnvalue: the set of all subsets of M.

Examples: If PP is the procedure,PP({}) returns {{}},PP({a}) returns {{},{a}},PP({a,b}) returns {{},{a},{b},{a,b}},PP({a,b,c}) returns {{},{a},{b},{c},{a,b},{a,c},{b,c},{a,b,c}},PP({a,b,c,d}) returns{{},{a},{b},{c},{d},{a,b},{a,c},{a,d},{b,c},{b,d},{c,d},{a,b,c},{a,b,d},{a,c,d},{b,c,d},{a,b,c,d}}.

 

you will be rewarded with a lifetime supply of grattitude if you can help me out! thanks.

Hi,

I need help for the following,

>