Hi - I'm trying to solve a PDE using pdsolve() for the Graetz problem (heat transfer in a pipe). I can solve the PDE and get a general solution, but when I try to solve the equation with the boundary conditions, Maple thinks that the boundary conditions are new functions with the same name. Here is how I am doing it now: > heat := (1-z^2)*(diff(T(y, z), y)) = (diff(z*(diff(T(y, z), z)), z))/z; > cond := T(0, z) = 0, T(y, 1) = 1, diff(T(y, 0), z) = 0; > PDE := [heat, cond]; > sol := pdsolve(PDE, T(y, z)); This throws the error:

I need to find the square root of a large number, x (about 70 digits long).  If I use x^0.5, the answer is displayed in scientific notation and  is rounded.  How can I find this number exactly?

I have 2 functions, f(x) and g(x) both continous on [a,b] (a known interval). For which value of C ε [a,b] the area under f(x) and g(x) is minimal?

I know f(x) and g(x).

I have 2 functions, f(x) and g(x) both continous on [a,b] (a known interval). For which value of C ε [a,b] the area under f(x) and g(x) is minimal?

I know f(x) and g(x).

In implicitplot, to insure the accuracy  of a curve, I usually increase the number of points (numpoints=*** ) or increase the number of grids ( grid=[***,***] ). Both can improve the quality of the curve. And sometimes one works better than the other. But I don't quite understand the relationship between the two options , and which is more effective and more economical. Thanks.

I want to plot  the astroid by the following code, but only the part in the first quadrant appears. I don't know that is wrong and how to solve the problem. Thanks.

with(plots):
a:=1:
implicitplot(x^(2/3)+y^(2/3)=a^(2/3),x=-a..a,y=-a..a);

Hello

I am running NLPSolve within a loop over some values of parameters. For one of the parameter values, the NLPSolve gives me

Error, (in Optimization:-NLPSolve) no improved point could be found
 

and exits the loop. How do I change this behaviour? I would like the loop to continue for other parameters.

I have tried interface(errorbreak=0) interface(errorcursor=false) but this didn't work.

Can anyone help please.

Thank you, Best Regards

Jan Zapal

 

 

Does Maple have a command for plotting  regular polygons? How can I plot a regular polygon insrcibed in a circle? Thanks.

By the way, I read from a book that an N-polygon can be plotted as follows. But I wonder if this is the easiest way.

with(plots):with(plottools):
R:=1:
C:=circle([0,0],R,color=red,thickness=3):
N:=7:
a:=I*(2*Pi*i/N+Pi/2):t:=R*exp(a):
P:=polygonplot([[seq([Re(t),Im(t)],i=1..N)]],color=blue):
display(C,P);

In Maple 11 I need to write define_external procedure with 23 arguments.

For example:
   test1 := define_external('myproc',
                                               N1::(integer[4]),

Hi

I'm trying to create a maple graded question for working out if a students response is a correct eigenvector. I've been trying to get maple to solve AX = LX where A is a 2x2 matrix and X is a column vector.

I've tried the following commands and although they work in the algorithms they don't seem to work when used to grade the question. It there anyway around this problem? I think the problem is with the MatrixMatrixMultiply command.

Hi

 

how can i do this in maple

 

if(a>b>c) then 4

 

or maybe if(a>b) and if(b>c) then 4

All:

This should be simple but I am clearly missing some of the nuances - can you please help me see what I am doing wrong?  I would like to solve 2 eqns in 2 unknowns:

eq15 := Kzeff15 = (Kvr*Kz15)/(Kvr+Kz15);

eq33 := Kzeff33 = (Kvr*Kz33)/(Kvr+Kz33);

Kz33 := (3.3/1.5)*Kz15;

Kzeff15 := 150612;

Kzeff33 := 253629;

soln_z15 := fsolve ({eq15,eq33},{Kvr,Kz15});

 

 

I am currently running Mac OS 10.5.2. (Leopard) Is there any version of Maple that works with this OS?

limit approaching infinity: (arcsin(x))/(x)

= 0

Question is: Why? The 'Sandwich Theorem' 0=[(arcsinx)/x]=0 gives this
solution, but looking at the graph of (arcsinx)/x , this appears
impossible.

lim x->OO [arcsin(x)] - {DNE)
lim x->OO [(arcsinx)/x] - {DNE/OO}

lim x->OO [-Pi/2x] = lim x->OO [(arcsinx)/x] = lim x->OO [Pi/2x]
=> 0 = [(arcsinx)/x] = 0

=> lim x->OO [(arcsinx)/x] = 0

HOWEVER: (-Pi/2)<[arcsinx]<(Pi/2) ... SO ... 

Greetings all

I would like to show the x y values next to the point on the plot does maple have a command to do this?

data := [[0, 0], [.5, -1], [1, 0], [2, 2], [3, 0], [5, -4], [7, 0], [11, 8], [15, 0], [18.5, -7], [22, 0], [24.5, 5], [27, 0]];
 with(CurveFitting);
cubfit := BSplineCurve(data, x, order = 3);
plots[display](plot(data, style = point, color = black, symbol = BOX),
plot(cubfit, x = 0 .. 27, thickness = 2))

 

tia sal