In the final line, my output is in the form of tau-c*z. How do I switch the tau-c*z back to 

zeta, because I want to integrate T with respect to zeta.

Thank you. 

> restart;
> with(plots); 
> U := V(zeta)*exp(I*(k*tau-w*z));
> zeta := tau-c*z; 
> Uz := diff(U, z);
> Utau := diff(U, tau);
> Utautau := diff(Utau, tau);
> P := convert(U, trig);
> 
> A := abs(P)^2;
> B := evalc(A);

When I used Maple to solve 3 constants in 3 integral equations, fsolve cannot give me the numerial solutions. It copied the equations and showed me “fsolve（......）”. But if I change the positions of 2terms in the equations (for example a+b is rewritten as b+a), fsolve can give me the numerical solutions for the 3 constants. 

In most cases, I donot know the right order and it cannot give me the results. So what is the problem?...

I'm using Linearalgebra and suppose I have a 10x10 matrix. I want to find the closest element in each column of the matrix to 100. Any idea how to do it?

I need to find the Killing vectors of a metric.

I initiate the session as

> restart;
> with(DifferentialGeometry); with(Tensor); with(LieAlgebras);
> DGsetup([t, r, z, phi], M);

and enter my metric as

M > g1 := evalDG(-dt &t dt ...);

I do not have an unknown function in my metric but I have two free parameters (e.g. a and b).

I use

M > K1 := KillingVectors(g1, parameters = [a, b]);

hi 

if I have two partition Pi and Pi 'I want to know the decomposition of Pi' 

Investigate the motion of a planet around a (fixed) star.

make 3D simulation

investigate the orbitals for diffrent initial conditions. Details and parameters

Help me,Plaese

q2.mw

Hi!

I have a question on result storage of for loop.  The program in attached.

The program is relative complex, it is not necessary to look part 1.

The question is in part 2.

The result I proposed is:

r=([17400,12500],[13900])

but, the real result of r is：

r=table([1.0=[1.0,17400,12500],2.0=[2.0,13900],()=[]])

what should I do to modify the program?

I am writing a procedure that takes the "output" of a call to dsolve (with the options numeric and listprocedure and without specifying a range of integration) as an argument ('dsol') together with a minimally acceptable range of integration ('tf'). The output of the procedure is either the input 'dsol' itself, if dsolve has been able to integrate from 0 to 'tf', or a modified version where the initial conditions have been modified.

Say I want to integrate an ode system [u,v,w...

I have plotted a predator/prey system using the following code and would now like to plot the same with the initial value problem of y=200, x=1000, with the end result being a graph of that one trajectory, without the phase field.  How can I do this?  Thanks.

DEtools[DEplot] ([diff(x(t), t) = 2*x(t)*(1-0.1e-3*x(t))-0.1e-1*x(t)*y(t), diff(y(t), t) = -.5*y(t)+0.1e-3*x(t)*y(t)], [x(t), y(t)], t=0 .. 10, x = 0 .. 11500, y = 0 .. 200, [[x(0) = 1000, y(0) = 200...

Dear all

I tried to intgrate this problem

P:=(b8*Omega^8+b6*Omega^6)/(a10*Omega^10+a8*Omega^8+a6*Omega^6+a4*Omega^4+a2*Omega^2+a0);

using these limits

Omega_r1:=beta*Omega_c;
Omega_r2:=(2-beta)*Omega_c;

assume((2-2*beta)*Omega_c>0);
assume(a0>0,a2>0,a4>0,a6>0,a8>0,a10>0,b6>0,b8>0,beta>0);
P_I:=evalf(int(P,Omega=Omega_r1..Omega_r2)):

but the results was not useful I got (RootOf)

Hi everyone,

I want to draw a phase portrait of a particle to see it moving but I don't want to see its trajectory. I don't know how to explain, here is what I did:

restart;with(DEtools), with(plots), with(linalg):

g11:=1;g21:=g11;

z:=exp(I*((t/(2*Pi))+(Pi*j)));

f1:=evalc(Re((I/(2*Pi))*((g11/(subs(j=1,z)-(x(t)+I*y(t))))+(g21/(subs(j=2,z)-(x(t)+I*y(t)))))));

q1:=evalc(-1*Im((I/(2*Pi))*((g11/(subs(j=1,z)-(x(t)+I*y(t...

hi 

I determined this whole partition but I just want to have the finer the 

I have a curve Tractrix: x(t)=1/cosht,y(t)=t-tanht

how I do?

• Find the length of the tangent line from the tangent point to the asymptote
• find the area between the curve and its asymptote
• find the length of the curve from x-axis to a point on the curve
• find the slope of the tangent line at any point along the curve

I hope you can help , its very important to me

kawakib

I'm working with some rather complicated sums involving absolute value, I'd like convert the sum into a piecewise defined function. For example

consider the line y=-x+1 on xy plane. the shortest line from the origin to y=-x+1 intersects with it at (x*,y*)=(0.5,0.5). Confirm this result by formulating and solving and optimization problem.