MaplePrimes Questions


I have used dsolve to obtain the solution of the inserted two systems below. The obtained results for the first system is accurate, where the obtaind solution of the second one is not accurate. I think the problem is in approximating the first system solution to be used in the second one. I would appreciate any advice on how to  obtain accurate results for the second system

 restart; endv := 5; sys0 := diff(f(x), `$`(x, 2...

Daer all! I want to solve the following equation

> H(z)*(1-m*H(0)^2*(1+z)^3/H(z)^2)-2*e*sqrt(1-c^2)*sqrt(r)*H(0) = 0;

where H(0) denotes the value of H(z) at z=0 and other constants are

> m := 0.211: c := 0.80: r := 0.338: e := 1:

If I want to use the fsolve command as

> eq := z->H*(1-m*H(0)^2*(1+z)^3/H^2)-2*e*sqrt(1-c^2)*sqrt(r)*H(0) = 0;

> Y := z-> fsolve(eq(z), H=1):  

what should I imply instead of H(0)? 

Suppose I have the following expression:

u=a+bx

Now I want to determine a and b using the conditions:

at x=h, u=4;

at x=6, du/dx=4.

Can I do the same using MAPLE? If possible how can I do it. Where to look for it?

Thanks in advance.

Hi I teach in a high school. Basically I have found that if I ask a question like: Factorize fully (x4-y4), and use a MathContainer for both the question and the answer (to be filled by students), I can't find a way to see whether the students have fully factorized the expression. Suppose (x4-y4) is in MathContainer1 and MathContainer2 is to be filled in by students. Using the code:

if GetProperty('MathContainer1','expression'...

I used dsolve to obtain the solution of the attached two systems of ODEs, where the second system depends on the solution of the first one. The obtained results for the first system is accurate, where the obtaind solution of the second one is not accurate. I think the problem is using cubic spline approximation. I would appreciate any advice on how to  obtain accurate results for the second system

Dear guys! I have an equation as

> eq := z-> H*(1-m*h^2*H^(-2)*(1+z)^(3))-2*e*sqrt(1-c^2)*sqrt(r)*h=0:

where

> m := 0.211: h := 0.741: c := 0.80: r := 0.338: e := 1:

At this equation H is an unknown function of z, h is the value of H at z=0 and I want to obtain H(z) actually(for example the graph of H(z) for z=-1..5). So I did as following

> Y := z-> fsolve(eq(z), H=h):    **

plot(eval(H, H='Y(z)'), z=-1 .. 5);

hi

I need to plot the phase portrait of a hamiltonian of 4-dimensional phase-space, and I have an adiabatic invariant, i.e. one of the momenta is conserverd. 

I don't know how to replace a constant for the conserved momentum and plot the 2-dimensional phase space.

I am writiing 

sys := {diff(Y1(t), t) = -(diff(K, y1)), diff(Y2(t), t) = -(diff(K, y2)), diff(y1(t), t) = diff(K, Y1), diff(y2(t), t) = diff(K, Y2)}

and using the DEplot tool as 

Why does fsolve miss some solutions?  For instance fsolve(sqrt(x2+4x-3)=-1+2x,x) only finds solution x=2, whereas x=2/3 is also a solution.

Ratch

f(t)=(cost^3(t), sin^3(t));

 

how do you solve the [tangent T, normal, N, and binormal, B,
 from the curvature k and torsion t of the curve osculating plane] 
above drawn curve? Could you help me
 

How can I display an array in a Mathcontainer Component ?

Thank you very much!

In Igor's "Multivariate Distributions in Maple" http://www.maplesoft.com/applications/view.aspx?sid=6352
he shows how to calculate the Multivariate Normal Distribution. Below I have provided some data
for expected values, covariances etc for a 3 random variable distribution.

Now I try to find the Quantile (with probability 0.05) for such a distribution however Maple fails.
How can I find the Quantile (with probability 0.05...

I decided to graph the 649 as a set of single numbers just for fun.  However with my code at 4 numbers Maple 12 stops responding the memory is at 1426 M and 337 sec.   Most likely better with Maple 15, but probably a memory issue after all plotting 49*48*47*46*45*44 = 10068347520 points is a lot of points.

Here is what I have for the first three numbers.


a:=table():
l:=1:
for i from 1 to 49 do
  for j from 1 to 49 do
   for k from 1 to 49 do

MAPLE.doc

I want to eliminate the variable u_x from the two equations attached in the document MAPLE.doc. Here u_x and delta are both functions of x. Is it possible to do it in Maple. If possible, how do I do it?

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