Hi I am new to using Maple,

Mybe this is a very basic question.

I am trying to find solutions to the following nonlinear system of equations using fsolve.

This is the right hand side of a system of ODE.

nonlinearsystem.mwnonlinearsystem.mw

I do get two solutions for the given parameter values. My question are:

As discussed in http://www.mapleprimes.com/questions/144586-Op-Command-Isnt-Working-As-Expected , the indices change some time at run time so previously working command is not working for me.

I am trying to use 

eq3 := applyop( u->Parts( u, phi[i](y) ), { 1,10,13,20 }, eq2 );

which clearly use the 'op' to get operands from eq2, but since the indices change at every run or on some run, the code is useless. The problem is...

Hi all,

I am new to Maple and I have (possibly a simple) question. I'm solving 2 coupled differential equation, it all goes well, until I want to plot them.

I have the output in the following form:

sol = {w1(x) = [ -a*x^4+b*x^3-c*x]}, {w2(x) = [-d*x^4+e*x^3-f*x^2+gx-h]}

My goal is now to plot the solution in 1 figure with w1(x) between x=0..100000 and w2(x) between x=100000..150000

I have searched on the web for a way to get the formula's of w1(x...

Hello

I am trying to plot solution of ode0 together with the maximum and minimum values but I am having difficulty since the first plot is a solution and second is values. I should have a plot with two line one represent the solution of ode0 and second (the max an min). Any advise or suggestion?

This is the code:

> restart;
with(DEtools); with(plots); Nsols := 5; Ntstep := 10;
 k := 0; A := 0.37e-1; B := 0.2e-6;
ode0 := diff(U(t), t) = -(A+B*U(t))*U(t);

I don't understand why 'expand(x+y)^18' the smart popup work, but with 'expand(x+y)^19'  (or more then 19) i have no smart popups!

Any idea?

Thank you all

Hi 

I am a Matlab user and just started using maple because I need more precision for my calculations. I failed to make Matlab interface work, therefore, I am writing my codes from the begining. And I am having a problem with a nested for loop.

The thing that I am trying to make is (in Matlab)

for j=1:N;
    for i=mod(j-1,2):2:j;
D(i+1,j+1)=2*j;
    end
end

In maple I tried something like

Hi Maple Community!!

Using dsolve, Mathieu 15 gives me the following solutions:

Given that I have specific values for b, e and g. How can I plot x(t...

I have a matrix of order 14 with whose entries being variables about u_1 to u_12. I want to get its determinant, but it return no results. It explains that it is too big for maple to deal with. So I wonder how to deal with such kind of this problem?

Thank you very much for kind attention!

I am trying to solve a system of 4 odes by using the following program:

with(plots):

Pr:=6.2:Ha:=10^(-12):Nt:=0.1:Nb:=0.1:Nr:=0.1:Gr:=0.1:Ec:=0.1:Rb:=0.1:Lb:=1:Pe:=1:tw:=0.2:Le:=5:

fcns:={f(y),T(y),S(y),G(y)}:

sys:=diff(f(y),y$3)+f(y)*diff(f(y),y$2)-diff(f(y),y)*diff(f(y),y)-Ha*diff(f(y),y)+Gr*(T(y)-Nr*S(y)-Rb*G(y))=0,

diff(T(y),y$2)+Pr*f(y)*diff(T(y),y)+Nb*diff(S(y),y)*diff(T(y),y)+Nt*diff(T(y),y$2)*diff(T(y),y$2)+Pr*Ec*(diff(f(y...

Hello

I am trying to find the maximum of values in dsolve. In part 1 we solve the equation. In part 2 we do a doolop to know the values for specific time such as t=2. In part 3 we try to give this values names such as y[i] then to find the maximum of these values but it did not work for the maximum it gave y6 instead of the value.

Also, is it possible to save all values from dsolve  to a file the call it to find the maximum at each t?

Hi! I have a matrix A where the entries

satisfy the conditions in eq1. I set A equal

to the general

4x4 matrix X and convert to a set so that I can 

solve the system of equations for the variables

in A (i.e. solve for a,b,c,d, s,t,r,l). However,

in my program below, I get "res:= "

when the program finishes. Why isn't it

giving me any output? Thanks!

Please help me in this integration. It does not work.  

restart;with(LinearAlgebra); with(linalg);

Q := x->0.5*erfc(x/sqrt(2));

rho:=0.25;sigma := 0.3;

m1 := sigma*sigma*Matrix(3, 3, [1, rho, rho^2, rho, 1, rho, rho^2, rho, 1]);

SNR := 15; mu := evalf(10^(.1*SNR));

 a := Matrix(1, 3, [(ln(y/mu)+4*sigma^2)^2, (ln(y1/mu)+4*sigma^2)^2,

 (ln(y2/mu)+4*sigma^2)^2]);

having its diameter equal to three and its number of vertices equal to 32? Is it possible to find the one with Maple? The simpleminded approach
>with(GraphTheory):
>with(RandomGraphs):
> G := RandomRegularGraph(32, 4);
> Diameter(G);
produces 4 or 5.
What I know is http://www-ma4.upc.es/~comellas/delta-d/desc_g/desc_g3.html ( the second graph).

 In the following root finding code, the wn[1] is calculated as [] although it is within the specified range. would you please tell me why?

integrate ∫dx/√((x^2+1)(ln(x^2+√(x^2+1)))