Hello,

I’m just toying around with diff(), dsolve(), and, as it happens, also with pdsolve(). Let’s say I have an equation as the following:

DF := (diff(f(x, y, t), `$`(x, 2)))*omega+(diff(f(x, y, t), `$`(y, 2)))^2+diff(f(x(t), y(t), t), t) = 5;

A function f, depending on x, y and t where x and y also depend on t. I multiply the second partial derivative of f by x with ω, add it to the square of the second partial derivative of f by...

Hi there,

can anybody tell me why this code works..

restart: with(DynamicSystems): alias(delta = Dirac): alias(sigma = Heaviside): interface(imaginaryunit = j):
DGL := 2*(diff(x(t), t))+10*x(t) = 5*y(t):
sys1:=DiffEquation(DGL, inputvariable=[y(t)], outputvariable=[x(t)]):
BodePlot(sys1, thickness = 2);

and this code doesnt'

restart: with(DynamicSystems): alias(delta = Dirac): alias(sigma = Heaviside...

Dear all,

I'm trying to derive the equation of motion for a mechanical system using lagrange equation

I do have u := sum(sum(U[2*i, n](t)*sin((2*I)*pi*x/a)*sin(n*pi*y/b), n = 1 .. 1), i = 1 .. 1); so u is a function of (x,y,t) but U is function of t only.

T:=subs(x = (1/2)*a, diff(u, t))^2;

Therefore T is function of (x,y,t)  and it has terms containing U(t) and d/dt(U(t))

now I need to differentiate T with respect to d/dt(U(t)) .

gam := 1.4;
p[L] := 1;
u[L] := 0;
rho[L] := 1;
p[R] := 1;
u[R] := 1;
rho[R] := 1;
p1 = 1/2*(p[L]+p[R]);
A[L] := 2/((gam+1)*rho[L]);
A[R] := 2/((gam+1)*rho[R]);
B[L] := (gam-1)*p[L]/(gam+1);
B[R] := (gam-1)*p[R]/(gam+1);
a[L] := (gam*p[L]/rho[L])^(1/2);
a[R] := (gam*p[R]/rho[R])^(1/2);
if p1 > p[L] then
     f[L] := (p1-p[L])*(A[L]/(p1+B[L]))^(1/2);
     df[L] := (A[L]/(p1+B[L...

when i type in the command plot3d(sin(x*y),x=-Pi..Pi,y=-x..x) maple keeps returning error. why is that so?

Hi Everyone,

I'm wondering if anyone here has had a similar experience.

I assign Maple projects to my students in table format.  They do their work in the first column and I write my comments in the second column.

I noticed that while I grade a worksheet (Maple 14 on a Windows 7 laptop), Maple becomes very sluggish.  I started monitoring  Maple's memory usage while editing.  When I open the file, the memory footprint is roughly 60,000K....

I just bought an HP 8500A 910A printer. So far every other application except Maple prints correctly and well. When I print, each (whole) page is printed in the upper left hand quarter of a letter size sheet of paper. This never happened with my old HP LaserJet 4L. After much search, there do not seem to be any setable preferences that could lead to this result.

On the HP forum, there is another user with the same problem except the application is different....

Hi all,

I have this two equations:

ap[k]=Sum(a[n]*sin(n*theta)*f(n,k),n=1..nn);

a[n]=Sum(ap[k]*g(n,k),k=1..kk);

Where ap[k] and a[n] are the unknowns.

I want to convert the two equations in the Matrix form A*X=b to solve it numerically and where X=[ap[k, k=1..kk] and a[n, n=1..nn]] and A the matrix with a rand (nn+kk,nn+kk) the coef and b the second member and a vector (nn+kk)

Thank you for any help to do this with Maple

I want to use the poset package on Maple 14 but am having trouble installing it. Could someone give me a heads up.

Thanks

0 = 0, -(1/16)*cos(l1)*cos(l2)*cos(l3)*cos(l4)*(-Pi*x3+4*cos(Pi*t)) = 0, -(1/16)*cos(l1)*cos(l2)*cos(l3)*cos(l4)*(-Pi*x2+4*sin(Pi*t)) = 0, (1/16)*cos(l1)*cos(l2)*cos(l3)*cos(l4) = 0, 0 = 0, -(1/8)*cos(l1)*cos(l3)*cos(l4)*(-Pi*x3+4*cos(Pi*t)) = 0, -(1/8)*cos(l1)*cos(l2)*cos(l4)*(-Pi*x2+4*sin(Pi*t)) = 0, (1/8)*cos(l1)*cos(l2)*cos(l3) = 0

After I ran solve({eq1, eq2, eq3, eq4, eq5, eq6, eq7, eq8}, {l1, l2, l3, l4, t, x1, x2, x3}, AllSolutions); I got...

If i have the line:

S:=Sum( 1/16^k))*(4/(8*k+1)-2/ (8*k+4)-1/ (8*k+5)-1/ (8*k+6)), k=0..m);

and i want to establish the first m for which |Pi-Sm|<= 10^(-8)

when putting it into a while loop i get the error message that it cannot determine whether the expression is true or false:

while (Pi-S <= 10^(-8)) do

od;

etc,

what am i doing wrong here?

I have a set of functions and parameters, I am computing Jacobian to those functions. I get a matrix rectangular in dimensions. So, determine Jacobian of sub-matrices(formed by removing one column for each sub-matrix) and equating them to zero.

> T := Matrix([[0], [4*t], [0]]); X := Matrix([[x1], [x2], [x3]]); R := Matrix([[1, 0, 0], [0, cos(pi*t), -sin(pi*t)], [0, sin(pi*t), cos(pi*t)]]);

> c1 := x1^2+x2^2-1/4-(1/4)*sin(l1); c2 := x3-sin(l2); c3 := t-1/2-(1/2)*sin(l3);>

In the help, a structure block diagram is given under the DynamicSystems[SystemConnect] command for the explaination of the use for the general connection,

that's intuitive and gives clear connections among every structure block,

so, I wonder whether there is a method to build that diagram or similar fig using the GraphTheory package,

that will be amazing,

is there a method? I want to know how to get it.

this is the model of my laptop : Sony VAIO VGN-FE590P

http://www.computercrowd.com/Itm160503097051_177_Sony_VAIO_VGN-FE590P.aspx

http://esupport.sony.com/US/perl/swu-list.pl?mdl=VGNFE590P

I am going to work with maple 14 on it , 
please check its hardware details !
and tell me usually a laptop with this condition ...

GCD := proc (a, b) local sol, x, y, eqs, vars; vars := [x, y]; eqs := [Typesetting:-delayDotProduct(cos(x), sin(y)) = 0, y+sin(x) = b]; sol := solve(eqs, vars); sol end proc

I tried to convert this code into C, using C(GCD) and got an error message that target language may not recognize commands like solve etc., which is obvious. Please let me know if there is any way to convert procedures involving such commands into C code.