See attached.  I am not sure but I think eq #4 is the same as the HESSIAN operator.  Why can I not get MAPLE to express this in the form of a matrix with the NABLA command? Note the discrepancy of NABLA with theDELoperator as well shown by eq's 5 & 6.

Am I missing some command to get NABLA to carry out the correct operation or am I not interpreting what NABLA actually is?

regards

Hi 

I want to make a 3D-plot with the style "surfacecontour". My question is: How do I define the number of contourlines? As I understand the default value is 10, but I only want 4. 

I hope you can help me!  

underline is a simple procedure:
> s := solve({5*A+3*B = 5, 8*A-9*B = 94}, [A, B]);
s := [[A = 109/23, B = -430/69]]
> assign(s);
> A; B;
109/23
-430/69

But, now what I want to use is not 109/23 or -430/69, but A or B.
That is to say, firstly, I need use root of equation, so Execute Command
> assign(s);
> A; B;
then, I can apply 109/23 or -430/69. Then later on, I want to use A or B, which now are viewed asariable? Now how can I do?

Hello.
A simple procedure:
> restart;
> A := Array([1, 2, 3,4,5,6])
> for i from 1 to 6 do
   B[i]:=2*A[i];
    od;
This procedure is runed, the results are
B[1] := 2
B[2] := 4
B[3] := 6
B[4] := 8
B[5] := 10
B[6] := 12

However, what I want is:
If A is saved in a arbitrary folder, for example c:\myp\*.txt(or excel,dat), how can I read these data?
Then, if I want last results to be saved in a folder, for example c:\myp\*.txt...

Hello everyone

i forgot to add, subtract, divid and multiple all infinties (∞) together and with any number and i want to know the indetermanite forms.

if anyone know, please try to respond quickly.

thank you all.

Latex to maple

I have the latex code

\lim_{(x,y)\rightarrow (0,0)}\frac{e^x+e^y}{\cos x-\sin y}

Can this latex language allow the entry of Ctrl+V

Hi, all of you.
I'm an engineering college student. And this is my first time to check the roots using the Maple.
But I tired to solve simultaneous equations and got  into some difficulties.

Acutually I'd like to get 6 roots[ A[i], t[i], i=(1,2,3).
Initial values are A[1]+A[2]+A[3]=1 and t[1]=0.

So I've simplified for 4 equations to get 4 root and to ask you.
Below, there is my code to get A[2], A[3], t[2] and t[3]. But it doesn't work well.

Hi,

I am using Maple 13 (hoping to upgrade soon) under Windows 7.

The open file dialog looks a bit weird, as per the illustration. Is this a known bug, and has it been fixed up in subsequent versions of Maple ?

thanks,
Andrew

Up until now, I have been using lists instead of sets in solve() in order to ensure the first equation is solved for the first variable, the second for the second, etc.  However, I have run into a case for which using an equation list and a variable list does not work, but the equation list alone is fine, and sets of both are fine, etc.  I would be grateful if somebody can explain why the first statement below does not produce a solution.

> soln := solve([foc1 = 0, foc2 = 0, foc3 = 0...

At one step of my code I need to define an array of functions which I will later use.

Simplified version of it to highlight the problem:

restart:with(linalg):
procG:=proc(a,b) if a>b then a-b else 0 end if end proc:
F:=vector(2):
for i from 1 to 2 do F[i]:=x->i*procG(x,0) end;

In the actual code array is much bigger and the expression for each function is much more complicated so using the cycle is a real 'must'.

Instead of F[1...

Hey,

i have 2 differential equations and want to solve the first one when x is positive and the second when x ist negativ. For this problem i wrote the follwing procedure. But when i try i have the posted error. Has someone a good idea to help me?

Thanks a lot

> DGL3 := 10*(D(D(x)))(t) = x(t);

> DGL4 := 10*(D(D(x)))(t)+5000 = x(t);

Tsolver:=proc()
global DG1, DG2, func, var, var_min, var_max, x, Dx, N:

I need to determine the general solution of the system of differential equations.

System of equations:

dx/dt = 2x-2z

dy/dt = 2y+2z

dz/dt = -2x+2y+4z

Thanks for the help!

for example:

>>simplify(cos(i)*sin(u)/sin(i),trig)

                    cos(i)*sin(u)/sin(i)

Maple do'not  simplify cos(i)/sin(i)=ctan(i) atomaticly.

also  half angle formulas:

>>simplify(sin(i)/(cos(i)+1),trig)

           sin(i)/(cos(i)+1)

i want to get tan(i/f)