Hi.

Does anyone know, why or when to use the assume command as opposed to just defining the assumptions?

e.g.

instead of typing:

assume(0 < sigma);

i could just write:

0 < sigma;

right?

I am not able to use colors flexibly in contourplot3d. So, I am trying another way to get my plot. But I am not exactly getting my result. This is what I am trying to do. I need help with these three steps. 1) For Latitude from -10 degrees to 10 degrees and longitude from -30 degrees to 30 degrees, I need to calculate aa:=1.4*cos(latitude)-2*sin(longitude). 2)The above value of 'aa' gives color. (eg. if aa<><><>3 color= red etc) 3) Then plot this point with color from step 2 at (x,y) given by

Hi,
not being used to work with Maple, I cannot figure out how to solve the following problem.

I want to verify if the positive semidefiniteness of a given 20x20 matrix A (depending on 10 real variables x_1, ..., x_10) implies the positive semidefiniteness of another 4x4 matrix B (depending on the same 10 variables). The entries of each matrix are linear in the given variables, at most depending on 3 variables. The 20x20 matrix is rather sparse.

What I tried is the following:

Hello, In maple, I am defining a differential equation similar to: (x^2)*diff(y(x), x$2)+x*diff(y(x),x)= a cubic in y(x). When I try to solve this using dsolve, numeric, I receive some form of memory error, stating that something small*I cannot be stored in datatype = float[8]. Sorry this isn't too specific - if you need more info or the boundary conditions, or perhaps the error message word-for-word, I'll reply with it when I get to my other laptop. Thank you very much for your help in advance, Marc

i have two questions here 1st how to do for llop and save the results in array or vector like : > for i to 5 do f[i] := 5.*i end do; the 2nd question is how to take the square root of each element of a give matrix like: A:=Matrix(9,9,9) how to take sqrt of elements to make it (9,9,3) ,and if i have two matrices A(9,9) and another one B(9,9), how to divide each element of A to its corresponding value in B???? i know maybe they are easy questions ,but iam just beginner .

hi, i have been trying to solve this. x^2 = 670 (mod 291). or x^2 - 291*y = 670. I have been trying to find x^2 manually, but it is taking a lot of time. is there any program that could go through the square numbers from 1, 2, ..., 291 to find x^2 = 670 (mod 291). many thanx, antonio

why the following returns false? > 2*Pi*V*(2*m)^(3/2)*sqrt(Pi)/(h^3*(2*beta^(3/2))) = V/(h/(2*Pi*m/beta)^(1/2))^3; "(->)" false "(->)" (3/2) (1/2) (3/2) (3/2) (1/2) (3/2) 2 Pi V 2 m 2 Pi V 2 m ------------------------- = ------------------------- 3 (3/2) 3 (3/2) h beta h beta

I am plotting flux values using contourplot3d. But I am only allowed to give two colors in contourplot3d option (eg. coloring=[red, blue]). This gives a contour plot that is a combination of these two colors. eg. But i want different colors to denote different flux ranges and so I need atleast 4 colors. Is there anything I can do? Thanks

Hello, I have about 80 equations for x and 80 equations for y. They are called S_{x_0} .. S_{x_80} for x and S_{y_0} .. S_{y_80}. They all depend on parameter m.

I want to define a new piecewise function P such as,

P evaluated at m=i  is equal to [  S_{x_floor(i)} evaluated at i , S_{y_floor(i)} evaluated at i ]

For example,

Hi

I want to derive an incompressible Navier Stokes equations with Maple for Conical Coordinate System.

In the beginning I'd like to derive NS equations in the Cartesian coord. system:

 

with(Student[VectorCalculus]):

V:=VectorField();

NS:=Diff(V,t)+DirectionalDiff((V . Del),V)=-Gradient(P)/ro+ni*Del . Del . V

 

Obviously something wrong with this writing.

Please help

Mark

Hi all,

 

I want to know how to represent a summation of the form:

and solve for x_n.

My reason is that I want to solve:for y_n where MU_x is the average for x ditto for MU_y.

 

Thanks!

i have a question with plotting i have a vector X of length (10) and matrix U, that its size is (10,20), how can i plot the vector X with each column in matrix U in the same figure ????????????????

Hello

I wonder how the following piecewise function can be plot in maple (showing the dirac function).

f := piecewise(t < 0, 0, and (t >= 0, t < 1), 1, and (t >= 1, t < 2), (-2+t)^2, t > 2, t = 4, Dirac(t-4))

plot(f,t=-10..10) does not show the dirac function.

Many thanks

Ed

PS.  I saw a solution using op but I could not follow what was done.