1. nonlinear ODE with parameter "epsilon"

(x^n +epsilon*y(x))dy/dx + n*x^(n-1) * y(x) =m*x^(m-1) ; y(1)=b>1

where n=2,3,4,.. and m=0,1,2,3,...

2. Duffing equation with parameter "epsilon"

d^2 y(x)/dx^2 + y(x) + epsilon*y(x)^3=0 ; y(0)=A ; y'(0)=0

Hi

I want to make my maple.ini file so that it sets plotoptions(discont=true) as starndard, so that I don't have to write it all the time.

I did it a couple of years ago, but can't make it work now.

Hope some of you can help me.

Regards

Michael

I don't think the geom3d package can be used symbolically it needs specific values.  Maybe I'm wrong, am I?

Hi,

I'm plotting this function of (x) which is very complicated expression anyway I plotted it..Now I want to plot the f(x)/max value of f(x)???

I appriciated for any advice...

Hi, im new with maple

so I am still a bit confused with how to use it..

i have an nonlinear ODE with parameter "b"

(x+b*y(x))dy/dx + y(x) =0 ; y(1)=1

if i want b=0.1 and x=0, 0.1, 0.2, ..,1

how do i

I want to find all values of m such that the equation (x-m)*(x-2*m-1)*(x+3*m-2)*(x+m+3)=0 has two positive solutions and two negative solutions. How to solve this problem with Maple?

Hello,

so I have the following function to be plotted:

M = (1+y^2)/((x^2+1)*(1+z^2))

Anyone have any background knowledge on the above 3D polynomial?  Assuming all 4 parameters are real I ploteed some 3D plots & some interesting surfaces are generated.  I imagine this has some physical application.  If anyone has some knowledge on this please respond & include any references you might know of.

Thanks

I tried using maple to solve the below system of Partial differential equations but itzz not jst coming out... any assistance will be appreciated (post the maple codes if used)

sys2 := -(diff(u(y, t), y, y)) + S*(diff(u(y, t), y)) + diff(u(y, t), t) + M.u(y,t) + (u(y,t)/k)-theta(y,t) = 0,
 -(diff(theta(y, t), y, y))/Pr + diff(theta(y, t), t) + S*(diff(theta(y, t), y)) = 0

The variables are... u(y,t) and theta(y,t)

The initial conditions are;

Hello,

I am having some trouble with a recursive formula which I instead turned into a loop to avoid any errors. I defined an array before starting the loop and defined the last index as a floating number (this will be the initial point used in the loop). Within the loop, I first defined my recursive formula (which contains other arrays that are indexed; everything is switched to floating points) and it equates without trouble. Underneath this (still within the loop...

Bonjour,

Comment calculer avec Maple une intégrale première de omega:=(x^2-y*(x+y^2))*dx+x*(x+y^2)*dy.

Merci d'avance,

Gérard.

Hi,

     I have a set of first order, linear ODE's in matrix form, I was able to solve them with matrixDE for 4 equations (which were uncoupled), but I would like to up this to around 132+ equations if possible. When I tried 9 equations I got

 Error, (in collect/series) integer too large in context    

on my laptop and on my other computer it was very slow and I didn't wait for a solution. 

Should I try a numerical solution ...

> with(PDEtools):
> declare(y(x), prime=x):
> ode := diff(diff(y(x),x),x)*diff(y(x),x)*y(x)*f(x)-2*diff(y(x),x)^3*x^6> + 2*diff(y(x),x)^2*y(x)*diff(g(x),x) + y(x)^5; 
 diff(ode,diff(y(x),x));
Error, invalid input: diff received diff(y(x),x), which is not valid for its 2nd argument

 i want to make deravatition with respect to the first deravatives,what should i do? 

Say I wanted to print out all values from 1 to 8 but excluding 3, how would I do that using a for loop?

For example, this just stops after 2:

for i to 8 while i <> 3 do
print(i);
end do ;

whereas I want it to skip 3 so going 1,2,4,5,6,7,8.

For what I'm actually doing, I need i to run over a range but excluding one value.

Thanks!

I am not sure if this is a general problem.  And I am considering the best way to evaluate the expression (Equation) when it contains variables which have been modified by using assume.   Here is a tiny test example:

restart;
assume(a>0,x>0);
int(int(x^2/y^2,y=1/x..x),x=1..a);S:=%:  
                        1  4   1   1  2