I'm using Maple2019.

Here is my code:

with(geometry);
point(o, 0, 0);
point(A, 0, 1);
point(d, 0, 2);
point(F, 0.8944271920, 1.4472135960);
line(lOD, [o, d]);
line(lAF, [A, F]);
alpha := FindAngle(lOD, lAF);
 =
                      alpha := 2.034443936

FindAngle is supposed to return the smaller angle between two lines.

Here it is greater than Pi/2

How can that be ?

Thank you for your advice

Hello, I was wondering about the following.

cos(Pi/2^n) can be converted to a radical for each integer n, because cos(Pi/2)=0 is known and successively

cos(x)=sqrt( (1+cos(2x))/2 )

so in principle radical expressions should exist for all integers n. But maple only converts cos(Pi/8) to a radical, but not cos(Pi/16) and higher powers. Is there a simple way without writing an own program to obtain these radical expressions using convert(*,radical)?

restart;
with(LinearAlgebra):
with(VariationalCalculus):
# Energie cinetique/potentiel
T := 0.5*m*(diff(r(t),t)^2+r(t)^2*diff(theta(t),t)^2)+(1/6)*m[0]*l^2*diff(theta(t),t)^2;
Ve := 0.5*k*(r(t)-r[o])^2;
Vg := -m*g*r(t)*cos(theta(t)) - 0.5*m[o]*g*l*cos(theta(t));
# Lagrangien
L := T - (Ve + Vg);
E := EulerLagrange(L,t,[theta(t),r(t)]);
EQ1:=simplify(E[1]);
EQ2:=simplify(E[2]);
dsolve({EQ1,EQ2,D(theta)(0)=0,D(r)(0)=0,theta(0)=0,r(0)=10},{r(t),theta(t)});
dsolve({EQ1,EQ2},{r(t),theta(t)});

Hello ! 

I'm currently trying to learn some advanced mechanics with the Lagrangian method. I'm ok with the physics part. I can solve small problems by hand but when I try it on maple, it won't work.

The equations I'm using have no mistakes, I'm following a book step by step. 

What I'm stuck with is to get a formula of theta and r that are only function of time (t) to then be able to plot it. And I need dsolve to work to get that.

As of last week using Maple 2019, and now with Maple 2020, I have begun to have issues trying to export rendered plots using plot3d. Even trying a simple example such as:

plot3d(x^2+y^2, x=0..1, y=0..1); 

will return the correct 3D plot, but right-clicking the plot closes the program immediately. Has anyone else experienced a similar issue? 

I am trying to graph x^(1/2) and (x^2/8) revolving around the y-axis using the ring method but I have not been able to do it. I only get the shell method. I have adjusted the functions to read x=y^2 and x=sqrt(8y). The bounds for this method is 0 to 2. No matter the commands I have tried I have not been able to get the washer method to show. I do not want to use the tutor program.

Can someone help me with the following question?

I would like to plot the function f(x)=a*x*(1-x)+x*ln(x)+(1-x)ln(1-x) in the interval [x1,x2], where x1 and x2 are points that satisfy the following: df/dx(x=x1)=df/dx(x=x2)=0 and f(x1)=f(x2), where a is some parameter that is greater than 0.

I guess I need to use here fsolve, but I am not sure how.

x:=Proc
Local a,
b,

C;
use XML Tools in 
end use;

end proc;

Hello,

I have a problem, please help me to solve it.

I am trying to extract coefficients of some polynomial expressions but I receive Error.

For example:

>with(Physics):

>Setup(mathematicalnotation = true)

>S := a*(x^2)+b*x+c*(1/(x-h)):

>Coefficients(S, x, 1)

>Error, (in Physics:-Coefficients) unable to compute coeff.

**** Note that if instead of the term (1/(x-h)) we have (1/x), then we get the true result. The error occurs only when we have some extra things in the denominator namely "-h".

Regards

How to learn Maple Programming effectively, whether Python will help?

My objective is to write a procedure that will read data from xml at different mentioned condition, read ICBO value at different condition of VGS i.e ICBO value at VGS=5V

BJT_ICBO := proc(parsedXML, VGS at condition )
 

end proc;

can some one help me to write procedure 

In maple, how to change strings style? Thanks!  

In Mathematica , we can choose Style to change strings style.

source of the  problem : I make an User Interface.

the color of   "mass "  may consider be changed to  red . 

Hi, can someone explain me why CodeGeneration in C throws the error : Error, (in Print) improper op or subscript selector ? Interestingly, CodeGeneration in Python or Matlab works. Source code is attached. Thanks in advance!

membrane_energy.mw
 

Download membrane_energy.mw

Hello experts,

I am trying to use solve to find a solution to a system of two equations. The two equations involved are quite complicated, and so sometimes Maple has difficulty with this. In particular, the solve command tries evaluating but never comes up with a solution (I've waited at least an hour, before giving up). 

I recently learned about fsolve, which gives approximate numeric solutions (which would be fine for my purposes), but fsolve too struggles with a solution and simply returns my input to me. I tried plotting the system of equations using plots:-implictplot to see if a solution existed, and as expected it does. I was hoping to get some tips on trying to solve a difficult system like this, perhaps given the knowledge that a solution definitely exists. Unfortunately, I need a solution for many variations of the same system, so simply reading off the approximate solution isn't really an option.

In my attatched code, the system with W = 49 is the first one where Maple really begins to struggle, and I believe that solutions for W>49 are also difficult.

06042020_Predicting_w_AB_Ratio_Maple_Primes.mw

Thanks!

Hello again, it's my first time using maple, so I have more problems :(

I need solve three equations, but maple shows an error:

Error, (in solve) a constant is invalid as a variable, gamma

gamma.mw

I have used g instead of gamma and solve works, but I don't understand what happen.

The second problem is when I use g instead of gamma. In some tau values solve() doesn't show the solution. In each solve() always there are one unnecessary equation. Maybe could be that. But I don't know.

g.mw

Thank you in advance!!!

P.S. Sorry for my bad English

 Hello! I'm trying to solve the following: 

Unfortunately, after calling pdsolve , I get an empty result set . Can you help me figure out what's going on?  Does it  really have no solution?