I created a null tetrad, but Maple's GRQuery returns false.  Here is the code:

Hi,

I'm trying to compute the mean and variance of a custom discrete random variable, as indicated in the file below (well, I do know its mean and variance, but I need the variable in a more complex context). Defining it is no problem at all, but when I parse Mean(Y) and Variance(Y), a weird expression shows up, despite my random variable being really simple. Does somebody know what goes wrong?

am having my graph in points but i want it to plot surface from these points 2d_curent_heating_fd.mw

please let me know which commands to use here

sol := solve(f);

sol := [3, 1+2I, 1-2I];

would like to consider 1+2I and 1-2I is the same thing

however repetition not work in this case

would like to check this in if statment and count add one when meet this condition

as there are many equations to check

i interpolate data and result in 96 equations

and then solve them and saved their roots into Vector roo, each of roo has 3 roots

and would like to animate first root of 96 equations, second root of 96 equations to see how roots move 

however meet difficulty when animate, how to animate this

moreover, is it possible to slow down the anime when playing it

> roo; Vector(4, {(1) = ` 1 .. 99 `*Vector[column], (2) = `Data Type: `*anything, (3...

> rtable_num_elems(FindRepetitions([1, 2, 1]));

Error, rtable expected

> rtable_num_elems(convert(FindRepetitions([1, 2, 1]),list));

hope to use if statement to check if number of repetition great than 0 then set true

Hello,

This method works in 2d... but in 3d I get a HFloat undefined output when I try and substitute the actual values in to the function. If anyone could have look through the programming and see why this is, it would be really helpful!

Thanks,

Rach:)

The_Whole_Program_I.mw

1. which command can check the result of solve command has repeated roots?

2. which command can check the result of solve command has zero roots? is it only find whether contains zero in the list? which command is to check contains zero in the result in solve

     Many times when I use dsolve to find the solution of an equation like x-y/y' = y , I get a term involving the LambertW function.  However, the equation has homogeneous coefficients for dx and dy, so it can easily be solved by substituting y=u*x and separating the variables.  The closed form solution of the above is x+y*ln(y)+c*y = 0 , but I cannot get that answer from Maple.  Is there...

I need to solve the following equation:

>restart;
>z := a+b*y*conjugate(y) = 0;

where y*conjugate(y) is unknown. How to solve it or how to eliminate y*conjugate(y) from the equation?

Thank you.

In the "solve" expression below, I am puzzled why the Maple solution has the natural log argument

((Voh-Vthl) / (Voh-Vtlh)

rather than

((Vthl-Voh) / (Vtlh-Voh)

as I would have expected;

solve(Vthl = Voh + (Vtlh - Voh) * exp-(t / t1), t)

?

Thank you

I need to graph x^3-xy+y^3=7 and y=-11(x-2)-1 on the same graph.

http://www.maplesoft.com/support/help/Maple/view.aspx?path=VectorCalculus/Divergence 

with(VectorCalculus):

SetCoordinate(cartesian[x, y, z]);

F := VectorField(<x^2,y^2,z^2>);

Divergence(F);

Error, (in VectorCalculus:-VectorField) no coordinate names were given

Error, (in Vector) dimension parameter is required for this form of initializer

Hi, was wondering if any of you could help me, when I try and find the real part of a function to plot, I get a float(undefined) error, however by just using evalf if gives gives me the real and comlex parts.

zetaroots.mw

The function i want to find realy parts for is f(x).

Thanks,

Matt

Hey,

I know this might seem a bit trivial but I'm trying to get Maple to use iteration to get the shortest path between two points given initial conditions that aren't a straight line. (I'm learning how to do it in the simplest form before moving on to a 3D problem.)

So I have a initial set of points that are to be moved during the process and split them into their x and y components so there's a set of x[j]'s and y[j]s.Then I defined a couple of procedures to use in the iteration.