## How to find the determinant..?...

I have matrix C: C:= matrix([[a,b,c],[d,e,f],[g,h,i]])=7; and want to find the determinant of matrix K. K:=matrix([[a+d,b+e,c+f],[d,e,f],[g,h,i]]); How do I do this? Im not very familiar with the linalg-package in Maple so I need help.

## 3D postcript figure acuracy...

I am exporting a 3D colored ps figure by using the output command: plotsetup(ps,plotoutput=`plot.ps`,plotoptions=`portrait,noborder,color=RGB`); Without changing the grid size, the figure, in the postcript file, appears with less accuracy than the one that would appear in the Maple environment. Is there an option to be defined that improves the picture resolution without the need of increasing the number of points of the grid?

## " More than just the answer"...

In the student part of maple 10, it says: " More than just the answer Maple 10, in addition to providing the answer, also displays all the required steps and the “thinking” behind the math problems you are facing." But I can't see anywhere in the program where this is available. Put something in and all it does is give you a final answer: One simple example: solve(y^2 = (x(x+1))/2); just gets you the final answer

## Help me please to draw graph of function by Maple,...

Hi everybody :)I'm a student and I study at Ha Noi University of Education in Viet Nam. I'm the 3rd student and I need a help, very pressing...My teacher ask me to search about Maple soft to draw a function graph like y=ax2+bx+c :( But I have to finish it in a short time,about 7 days, it's very difficult for me. I really nead a help. I write English not well so I can express my problem exactly, you can send me a mail through ankanheesun@gmail.com,thanks thanks a lot... It's very important with me,somebody help me...

## Problem: LinearAlgebra, Eigenvectors, MatrixExpon...

There must be an easy way to resolve this problem, I just haven't found it yet. > restart;with(LinearAlgebra); > A:=pp->eval(Matrix([[a1(p),0],[0,a2(p)]]),p=pp):A(p); [a1(p) 0 ] [ ] [ 0 a2(p)] > Eigenvectors(A(p)); Error, (in LinearAlgebra:-LA_Main:-Eigenvectors) expecting a Matrix of rationals, rational functions, algebraic numbers, or algebraic functions > Is there a way to make the LinearAlgebra routines treat a Matrix function just like a regular Matrix? thanks

## how to optimize a numerical function...

I have defined a function: ft(n,v)=Zeta(0,n+1,1-2*Pi*v*I)/Zeta(n+1) mag(n,v)=sqrt(ft(n,v)*conjugate(ft(n,v))) I want to find the points v at which mag(n,v)=0.5 (i.e. for n=2,3,4, etc.) Any of the so-called numerical solver techniques described in the help file with Maple simply return an expression containing the digamma function symbol (e.g. Psi) Any ideas? Thanks -Monty Wood

## Find the solution to a numerical function equation...

Find the solution to a numerical function equation? I have defined a function: f(n,v) = Zeta(0,n+1,1-2*Pi*v*I)/Zeta(n+1) mag(n,v) = sqrt(f(n,v)*conjugate(f(n,v)) For this funciton, n represents an integer, and v is real. Essentially, for different values of "n," I would like to find the numerical value of "v" at which mag(n,v) is equal to 0.5 Using various combinations of Optimize, fsolve, and NewtonsMethod, and interlacing evalf into the definitions, the program continues to give me a symbolic expression using the "Psi" symbol for the Digamma function. Is there a way to define the function strictly numerically so that the symbolic engine does not kick in?

## Solve multivariate polynomial equations...

Hello all! I need to solve multivariate polynomial equations modulo a positive integer 'm', where 'm' is not prime. Which function would be best? Also, how do I include constraints to the above set of equations? For instance, if I need to solve for 'x' and 'y' such that f(x,y) = 0 mod m g(x,y) = 0 mod m f != g mod m Any help would be great!!

## Plotting parametric function...

How can I plot the following function? x = cos(t) + 2*cos(2*t); y = sin(t) + 2*sin(2*t); To be clear this is one function. Thank you in advance.

## Replace exporting file names...

Hi, I'm new to Maple 10 and have a quick question. I am generating a whole load of numbers which I am writing out to files using the ExportVector command. I want to run the worksheet many times and replace the numbers in the file names each time. I have 80 file names each time and wanted to do this via the Find/Replace command but it only seems to find text rather than command inputs. My worksheet looks like this: > ExportVector("out_geg2.k015.e10_1n1.m", ans1a, target = Matlab, format = rectangular, transpose = false); > ExportVector("out_geg4.k015.e10_1n1.m", ans2a, target = Matlab, format = rectangular, transpose = false);

## Differential equations...

hi, I have a big problem with my project. I need a help with solving and plotting three differential equations but I can´t do it. The project is about lotka-volterra system with three species, 2 predators and 1 prey with no competition between predators. Thanks for a help. eqPrey := diff(X(t), t) = alpha1*X(t)*(1-X(t)/K) - beta1*X(t)*Y(t)-gamma*Y(t)*Z(t); eqPred1 := diff(Y(t), t) = -alpha2*Y(t) + beta2*X(t)*Y(t); eqPred2 := diff(Z(t), t) = -alpha3*Z(t) + beta3*Z(t)*Y(t);

## How do I simplify the matrix?...

Dear Sir/Madam: I try the following maple commands: > with(linalg): > A:=matrix([[r1*X, (1-r1)*X],[1-r2,r2]]): > eigsys:=eigenvectors(A); > ES:=eigsys;ES:=eigsys; > P:=augment(op(ES),op(ES)); > K:=map(simplify,evalm(inverse(P)&*A&*P)); > W:=map(simplify,evalm(P&*K&*inverse(P))); > U:=map(expand, W); > map(simplify,U); Now, K and P are correct because P&*K&*inverse(P) = A. But, when I use the following maple commands, I cannot get A^i with entries that are polynomials of r1 and r2 and X. > V:=map(simplify, evalm(P&*(K^i)&*inverse(P))); (Note: formula A^i = P*K^i* inverse of P is correct.)