When simulating an electrical circuit I decided to eliminate a subsystem block but later changed my mind. Now I'm unable to use the same name for the subsystem block as before despite the fact that there seems to be no place where it is used. Always an error "The name blabla is already in use". Can I somehow list all the names and the places where they are used?

I have been trying to do this for some while now but am not having much luck.

Basically what I need is a hermitian matrix, with real values on the diagonals X~N(0,1) and complex values on the off diagonals X~N(0,1/2)+i*N(0,1/2)

Obviously as its hermitian I need Xij = Xji*
 

I have tried a few things but can't get anything to work correctly, in my latest attempt I decided to try and construct the 2x2 case from scratch using if and for loops;

for i to n do

for j to n do

if i <> j then

restart; with(DEtools); phaseportrait([(D(x))(t) = -.1+x(t)^2-x(t)*y(t), (D(y))(t) = y(t)^2-x(t)^2-1], [x(t), y(t)], t = -10 .. 10, [[x(0) = 0, y(0) = 1], [x(-2) = -2, y(-2) = -1], [x(0) = 1, y(0) = 0], [x(0) = 0, y(0) = 0]], stepsize = 0.5e-2, scene = [x(t), y(t)], linecolor = t, x = -4 .. 4, y = -3 .. 3) I want to explicitly draw the hyperbola with arrows in the direction of the vector field. How do I obtain this? With the initial conditions I get solution curves that I dont want.

# Hello!
# I've been trying to replace one expression into another, which includes the derivative of a quotient, but algsubs doesn't work and I don't know why.
# To make it simple, I want to replace a expression from rho into the expression for q_x. Let's say rho is a function of alpha.
>
> restart;
> alias(rho = rho(x, y, t)); alias(rho_an = rho_an(x, y, t));
> alias(p = p(x, y, t));
> alias(q_x = q_x(x, y, t));
> alias(alpha = alpha(x, y, t));
>
>
> rho_an := alpha;

Can someone help me please? I cant find what is wrong. thank

View 16354_take13.mw on MapleNet or Download 16354_take13.mw
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Nash

how can i understand calculus own my own. and i'm a lazy student.

I need to write a loop within a loop for something like this;

for i from 1 to n for j from i to n do;
A[i,j]:= rand();
A[j,i]:= A[i,j]

end do; end do;

(just random sample code, not what I need to do)

But I don't want the loop to carry this out for when i=j ie. A[i,i] for i = 1 to n. How can I do this?

This is on Simple Harmonic Motion. I have
KE= 2*v(t)^2 ,
PE= 3*x(t)^2 + 4*x(t)^4.       and I also have given
diff(x(t),t) = v(t).

I needed help plotting it because I know that TE = PE + KE is a constant and I just want to plot it into a straight line. ( I have simplified the equations so don't worry about the equations being wrong).

 

Help Needed, really appreciated.

 

Thanks, 

 

Hi,

I tried to find the limit of the following equation using l'hopital's rule, when sigma approches to zero find i couldn't find it.

Now i want to use Taylor series to find the limit of the following equation, when sigma approches zero.

Hello! And thanks for looking and helping!

I've been working on programming an algorithm that requires that I find the polynomials A, B
such that Af + Bg=Res(f, g, x) [the resultant] where f and g are given. In all my searching I couldn't find something that would spit out A and B for me. No luck that route so...

Hi!

I've a problem with maple. I wonder to see the visualisation of the solutions of a system of partial equations :

with(PDEtools);
EDP := [diff(s(x, y, t), t) = -.45*i(x, y, t)*s(x, y, t), diff(i(x, y, t), t) = .45*i(x, y, t)*s(x, y, t)-.2*i(x, y, t)-.7*(diff(i(x, y, t), x)+diff(i(x, y, t), y))];
IBC := {s(0, y, t) = 1, s(x, y, 0) = f(x, y), i(x, y, 0) = g(x)};
f := proc (x) options operator, arrow; 1-g(x) end proc; g := proc (x) options operator, arrow; piecewise(x = 20, .2, 0) end proc

 

But when I write :

Hi

I have an old maple document written as 1-D math input. In order to make the document more clear I used the convert to 2-D math input funtion.

The following expression containing a unknown function phi[0] and a guess on this function has both been converted to 2-D math input.

U0:=1/2/mu*exp(-I*theta)*(kappa*phi[0](z)-z*conjugate(diff(phi[0](z),z))-conjugate(psi[0](z)));

phi[1](z) := A[1]*z^(lambda+I*epsilon)+B[1]*z^(lambda-I*epsilon);

hi,

I'm currently proctoring for my univeristy math dept.  They ask me to put policy on testing website.  Please help me how to do that? thanks,

Hi there, I'm trying to express the following expression

sin(c + I * (sin (d + k * sin(t)))

 

in terms of Bessel functions. I've been knocking my head against it trying to do it by hand for a while now and someone suggested maple could help.

Hello everybody!
 

I have a problem that's cracking my skull for the past few days and i can't seem to find an answer.
I have three equations with three variables, wich i have to solve.

> f1 := (x, y, l) -> x*z-l*x+2*z*l;

> f2 := (x, y, l) -> x^2+4*l*x;

> f3 := (x, y, l) -> -x^2+4*x*z-12;