How to subs t = cos(2*x) in expression A:= cos(x)^2 + cos(4*x)? Please help me. Thank you.

Firstly applogies for if this question has been asked before.

I am trying to plot a simple epidemic model for where I can change the rates.

My equations are:

de1:= diff(X(t),t)=a*X(t).Y(t);

de2:=diff(Y(t),t)=a*X(t).Y(t) - b*Y(t);

where X is susceptibles and Y is infected.

I would like to be able to produce a graph with the susceptible and infected plotted. Where i can change the initial conditions of X(0) and Y(0) using sliders...

Let r is radius of circle inscribed and R is radius of circle circumscribing atriangle ABC.

Prove that p[tan(A/2)+tan(A/2)+tan(A/2)]=r+4R where p=(1/2)(a+b+c).

I have two inequalities in the complex variable z, called "ineq" and "ineq2".  When I issue the following plotting command, I can show the region of the complex plane that satisfies both inequalities:  It appears as a black region:

plots[implicitplot](eval(ineq = ineq2, z = x+I*y), x = -8 .. 8, y = -8 .. 8, gridrefine = 3, filled = true)

Now, I would like to generate a similar overlap plot, but for three inequalities,...

Hi all,

I have some problems to model a DC-AC converter with transistor. Can some one take a look in my maplesim file and help to correct it

Thanks

transistor.msim

Hello,

I just bought a new PC with Windows 7 Professional 64bit and wanted to install my old Maple 12. I have a notebook with Windows 7 Home Premium 64bit where it runs without any problems. However, Maple 12 does not start whether I put it on compatibility mode or not. There are just two error messages showing up:

http://s14.directupload.net/images/120303/5xwxbl8j.png

http://s14.directupload.net/images/120303/ij8jqfdl.png

Maybe someone can help?

I have a question about the accuracy of Maple functions subs and evalf. I have some expressions such as the following: (more complicated). Let's call it f(n).  f(n) is not a polynomial in n or a rational function. It is a function of n involving exponents and four operations. When I plug in a large n in such an expression, would the answer I get (using evalf with some custom accuracy) be exact?  I am trying to prove f(n)/n >= constant....

Maple experts, please help...

I am facing hard time with ODE functions...:(
I would like to know if there is any command or algorith that could actually clear the solution of "dsolve" command,what I mean... let's say I have ODE function of one indeterminate "y(t)" and its general solution is obtained from dsolve command by setting certain initial conditions. Now, I need to remove that general solution from the system memory so as on next call of ODE function the "y(t...

Hi, can anyone help me with this questions? Thanks!

Use maple to find the general solution to the following system of linear equations:

2x₁  + x₂ - x₃ +3x₄ = 2

x₁ + 2x₂ -x₄ = -1

3x₁ +2x₂ -2x₃ +x₄ = 1

hi all

i am trying to write some code to display:

a) hexagon tiling, rather like a honeycomb in 2D

b)  equilateral triangles tiling , all space filled by said triangles. eg a series of triangles whose base is parallel to base of plot, with inverted triangles filling in the remaining spaces

c) square tiling

for a,b c I  want about 50 of each displayed (all of edge length 1) on the one plot

d)  some code...

My overall goal is to get a high resolution image onto a poster I am creating. I simply have an x and y coordinates for 4095 entries. Excel and maple can obviously do this, but I need to put the end result into PowerPoint. Since I think the Maple graphs look more professional, I was trying to use the Maple Add-In in Excel to simply make a scatter plot. I am assuming the image format between excel and PowerPoint will be much more compatible than that of maple to PowerPoint....

i have a D.E. systems:

J_n=2A_n

S_n+1=J_n

A_n+1=S_n+0.5A_n

and initial conditions A₀=10, J₀=30, S₀=5

can i use rsolve to solve this or is there another ways to solve this systems

One of my friends would like to buy a book about solving multiple integrals and/or ordinary differential equations with Maple (some newer version, let's say 13 and newer).

I know about this site: http://www.maplesoft.com/books/, but can anyone recommend some book(s) which is (are) worth buying?

I NEED YOUR HELP !!!

My computer is a DELL 755 optiplex with an intel video card : Integrated Intel® Graphics Media Accelerator 3100 The operating system is a  redhat Linux.

When I do this in xmaple 13 sofware :

plot(cos(x/2) + sin(2*x), x = 0..4*Pi);

all the windows shut down and I have this error :

X-Error GLXBadDrawable [resid=420029C opcode=(152,11)]

What are the equivalents of eval and evalf for Matricies. In particular how would you display a Matrix which appears in symbolic form to appear with numeric entries.