Dear all,

I am trying to find the intial velocity of a ball that is shot under an angle while only the start and end coordinates are given. The air resistance should also be taken into account. 

In order to do that I have build the following Maple sheet:

Assignment_question_1.mw 

I have used two differential equations that both include the variables v0 and t, and then try to solve them. Only I receive an answer in the form of RootOf, which I cannot remove with for example allvalues. 

I have been working for quite a long time on this but I am not coming any further, so is there anyone who can find what I am doing wrong/what I should be doing else? Or maybe my whole approach is not right?

Even a small step in the right direction would be appreciated a lot!

Thanks in advance,

Elise

How do I permanently change the current directory on a MAC computer?

Kind regards

Per Kirkegaard

Hi all

The aim of following program is minimization but it is unable to produce it. where is the mistake?

Taylor2.mws

thanks a lot.

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

Not sure if this is the right place to ask this (if not, where is?)

Suppose I ask a question and get an aswer with a variable such as F=_X+5_X^2+7 and want to sort it so as to get 

5_X^2+_X+7

If I try sort(F,_X) it will read the underscore as starting a subscript... I can just highlight copy and paste an _X from the previous answer, but that is silly.

Hello,

I would like to know how to generate super/subscript characters in axis label. I have tried the double underscore (atomic variable style) and the super/subscript under "Format" in document mode but no luck at all. Any comment/suggestion is truly appreciated.

Yu-Hung Lien

Hi guys,

If I have a Hermitian 4x4 Matrix with elements that behave like complex numbers except that they do NOT commute. Is it possible to diagonalize this Matrix using Maple and the Eigenvectors - method of the LinearAlgebra package?

Cheers

NOh

P.S.: I am using Maple 18

question: solve the direction field and curve that passes through each of indicated points.use different colours.

2)dy/dx=e^(-0.01xy^2)

(a) y(-6)=0

(b) y(0)=1

(c) y(0)=-4

(d) y(8)=-4

my answer:

> restart;
> with(DEtools);
> with(plots);
> a := diff(y(x), x) = exp(-0.1e-1*x*y(x)^2);
> g := dfieldplot(a, y(x), x = -8 .. 8, y(x) = -8 .. 8, color = exp(-0.1e-1*x*y(x)^2));

> ode := diff(y(x), x) = exp(-0.1e-1*x*y(x)^2);

> ics := y(0) = 1;
> dsolve({ics, ode});
  

it doesn't solve the ics n ode. actually i don't understand at all about dsolve bcoz this relating to exponential.

please do help me.thank you

btw before this someone do help me to solve my problem with this..here comes another problem..*sigh... thank you

u[0](x)=(1/GAMMA(0.5))*int((x-tau)^(0.5-1)*(tau^2+(tau^(1.5))*(8/(3))-tau-(2)*tau^0.5),tau=0..x);

I want to find the value of this integral

thank you 

Hello everyone,

I've been trying to do some perturbation theory and ran into some problems I don't quite understand. I implemented the Hamiltonian of the Bose-Hubbard model and treated the hopping as a perturbation. Calculating the second order energy shift is easily accomplished, but when I'm only interested in one of the two occuring terms, I run into problems. The calculation takes minutes to finally fail, giving me an "too many levels of recursion"-error. I need to be able to just pick a few terms for some calculations, I'm doing, and can't figure out what I might be doing wrong. Here is the source code (download is below):

Download too_many_levels_of_recursion.mw

It would be great, if someone could point out the mistake, I'm making. I copy/pasted the last line, so there shouldn't be any typos.

Thanks in advance,

Sören

Every time I try to solve for a variable it gives me an arrow.

ex solve(5.6*10^-4=((x)(x))/(0.2-x),x)

gives me

x -> 7/62500 - 7/12500 x

How do I get it to stop giving me the x -> ?

Or at least reset some options so I don't have to reinstall the whole thing?

> with(DEtools);
> with(plots);
> a := diff(y(x), x) = e(x)^(-0.1e-1*xy^2);

> g := dfieldplot(a, y(x), x = -8 .. 8, y(x) = -8 .. 8, color = e(x)^(-0.1e-1*xy^2));
Error, (in DEtools/dfieldplot) extra unknowns found: xy

how to solve this?
>
>

Hello,In short: I try to get the eigenvalues of a 16x16 complex matrix with one variable B__z. I know, the vales are very small (~10^-24), so I multiply with 10^24 and collect B__z. Now, when I use Eigenvalues(H) [H is the matrix] the result is just wrong:

test.mw

(same with original values) - compared to Mathematica which solves and plots in about 1 sec:

Where is the problem? What should I do? Any suggestions?

Hello,

first of all, this is my very fist question in this forum, so please excuse some formal mistakes I may make...

Using Maple 18.01 on Windows 7 64bit

To the topic: I want to calculate the eigenvalues of a complex matrix like this (just as an example):

M := Matrix(2, 2, {(1, 1) = a+2.5*I, (1, 2) = 1-I*a, (2, 1) = 4, (2, 2) = a})

When I try to calculate

Eigenvalues(M)

I get

Error, (in LinearAlgebra:-Eigenvalues) expecting either Matrices of rationals, rational functions, radical functions, algebraic numbers, or algebraic functions, or Matrices of complex(numeric) values

Strange, because if I replace the "2.5" with just "2", so an integer instead of a float, I get results:

I don't understand this strange behavior, since Mathematica i.e. calculates everything just fine...:

Thanks in advance for any suggestions.

How to get the equations of circles A, B, C, such as circle A with center (1,1) is drawn in the first quadrant.

Circle B with radius 2 and circle C are placed so that each circle is tangent to the other 2 circles and the x-axis.

THe 3 circles are on the first quadrant.

1) do it with Maple

2) do it by hand

3) draw the figure

Regards

solve([b+c = a*a1+b*a4+c*a7, a+c=a a2+b a5+c a8, a+b = a*a3+b*a6+c*a9], [a1,a2,a3,a4,a5,a6,a7,a8,a9]);

how to assume a1 to a9 are 0 or 1

and find one of possible matrix is

Expected Result := Matrix([[1,1,0],[1,0,1],[0,1,1]]);