## system of ode of predator prey models...

hi, i don't know maple at all and i need to figure out how to solve this sytem of equations that model predator prey systems in maple but i get an error when i modify this code > e1 := diff(x(t),t) = k*x(t) - a*x(t)*y(t); > e2 := diff(y(t),t) = -r*y(t) + b*x(t)*y(t); to fit this equation- dx/dt = 2x(1-x/4) - xy dy/dt = -3y + xy x(0) = 1 y(0) = 1 if anyone has time to tell me what i can do to get the equilibrium points, the solution and the table of values for this system, i would be grateful

## How do i solve Kirchoff's Law using maple...

I was wondering if someone can help me solve a problem of kirchoff's law using maple, heres the problem:

Use maple and Laplace transform to find the charge q(t) on the capacitor in an RC series circuit with the following conditions; graph q(t) on the interval 0<t<6 and use the graph to estimate the time and value of the maximum charge

q(0)=0
R=50 ohms
E is a piecewise where 1<x<3 = 100, everywhere else is zero
I'm assuming that since nothing is said about the inductance in the initial conditions, L=0

heres what i got so far:

>i(t):= diff(q(t),t);
>KirchoffLaw:=E[R]+E[L]+E[C]-E[emf]=0;

Does anyone know how to go about attempting this problem with Maple10 ? The question is the last line in bold type, and I tried to include as much relevant information as possible. To correct an error the second partial derivative should be with respect to time "t", not displacement z. so it should be (1/v)*(d^2/dt^2)f(z,t). sorry about the mistake. thx, Dan View 285_problem9.4Emag.mw on MapleNET or Download 285_problem9.4Emag.mw

## Appell Hypergeometric Function F2...

Hi, How can i compute the F2 Appell Hypergeometric Function using Maple? Can i write F2 as a function of the F1 appell function? Thank you. Appell Functions: http://mathworld.wolfram.com/AppellHypergeometricFunction.html

## reformulate a function?...

I have a function: fx:=5*x^4+16*x^3-24*x^2 for which to calculate roots I wish to reformulate fx to (x^2)*(5x^2+16x-24) Which command do I need to give maple to obtain this result?? Thanks in advance

## Turn loops into seqs with assign

by: Maple
Consider the following three problems: 1) given a list [a,b,c,d,e], return the list [a=1,b=2,c=3,d=4,e=5] 2) given a nested list [a, [b, [c, [d, [e]]]]] return the list [a,b,c,d,e] 3) given an integer in base 10, compute it's base b representation First I will show you what not to do:
```L := [a,b,c,d,e];
M := [];
for i from 1 to nops(L) do
M := [op(M), L[i]=i];
end do;
```
Building up lists (and sets) incrementally is quadratic time, because each iteration of the loop allocates linear storage to hold the new list. The standard solution is a loop with a temporary variable, assigning to a table:

## evaluating expressions...

How do I evaluate a result for a certain value for a variable? For example, int(sin(x),x) get me cos(x) in Maple. How do I ask Maple to evaluate cos(x) at , say, x=Pi/8 ? Thanks in advance.

## Plot a triangle?...

Hi, I have plotted the following triangle PLOT(POINTS([(-2,-4)],[(1,3)],[(2,-2)])); How do I get maple to connect these points? Is this the right way to plot a triangle, or is there a better way?? thanks in advance

## importing data and manipulating it...

ok, my first question, and as I only started using maple about 1hr ago, its probably rather a simple solution that I've missed. I'll tell you what i'm trying to do, and what I've tried so far. I've run some code which has given a formatted output of a lot of numerical data, in 4 columns (which I may wish to call x,y,T and P if I can). I wish to import this data into maple, so that I can eventually plot contour plots with it of T on a x and y grid, and P on an x and y grid. Having tried to use the readdata command to read the file in, I got a lot of row vectors. However I then couldn't find out how to reference specific values in these vectors to allow me to assign them to variable values, or maybe just directly plot them. I tried using the importmatrix command to see if that gave anything, but that failed entirely.

## Interface lockup with a fieldplot....

I know I haven't figured out all the limitations of Maple yet to avoid all the "gotcha"s but this should be straightforward, right? with (VectorCalculus): b(x,y,z) := VectorField(

## finding the extremes of a function?...

Hi all, Given two functions f(x)=x^2-1 and g(x)=2x+1 we can plot the following command restart:f:=x^2-1:g:=2*x+1:plot([(f),(g)],x=-2..4,y=-2..8); We have a local extreme of -1. Which command should I use to give me the local extreme where -2 <> 2?? Thanks in advance

## find all the prime numbers...

find all the prime numbers from 1 to 100 using if condition and loop bye maple 9.5

## draw a function as a dotted line?...

Hi, Given a function f(x)=x^2 i would type the following command restart:f:=x^2:plot(f,x=-10..10,y=0..10); how do I get the graph to show f(x) as a dotted line?? thanks in advance Robert