How do I get my actual solution which involves _Z? I have  tried answers that w ere given on questions related to _Z in a solution but mine is not working. I am completely new to Maple ,kindly help me.

Download maple_code_for_disease_equilibruim.mw

Hello 

I have a 3D vector plot with 3 vectors. It would be nice to have a legend for this, but so far, I have struggled to find a solution.

At the moment, I use a caption for this, but I am not fully happy with this.legend_question.mw 

Is there a simple solution?

Thanks in advance 

This time domain diagram has been drawn, but if you want to draw its outer outline, how should you command it?
saopinjifen1230.mw

Hello, I have a question regarding finding two vectors that result in a resulting vector with only the directions of the two needed vectors.

Given:

- Vector F_RC1

- Unit Vector of F_RC1Y (called EV_C1Y)

- Unit Vector of F_RC1_ST (called EV_C1_ST)

Needed

- F_RC1_ST

- F_RC1Y

The picture below and the file should make it clear. 

vector_question.mw

How do I approach this? Best regards,

Hello 

I am working on my vector file and have another question:

1. How do I display any vectors in a matrix notation next to each other or above each other (like: [1;2;3]) 

Find attached the file:question_vector_.mw

I really appreciate any help you can provide.

I have a simple question, but don't find a neat solution for it. I have 4 3d Vectors that result in the resulting Vector V5. I now want the unit vector of V5. How do I do it the most efficient way? 

My attempt is in the file attached. I get the error message: "Error, (in rtable/Power) exponentiation operation not defined for Vectors"

Thanks a lot for your help.3d_vector.mw

Hi!  I am trying to calculate a complex integral.  To double check my work, I directly coded the calculation.  The result is that the two results don't match.  Have I done something wrong?

here is the file

Complex_valued_integrals.mw

Is it possible to configure newer maple versions to use a different file extension ?

I have a lot of  Maple 9 files  with .mw extension. I dont want them opened and saved by a later version as they are valuable and actually work better than later maple versions which throws unneccesary signum errors. The results are verified so the signum errors are bogus in the recent maple versions running the same file.

Particularly, can I configure e.g. Maple 2022 to save to a different file extension say .mww or similar rather than .mw so I can avoid destroying to original 9.5 files?

Hi everyone!  I'm trying to study a certain function.  The output says that, from -5 to 5, the output is undefined.  Am I doing something wrong?

Thanks in advance.

range_not_undefined.mw

Solved a "simple" dynamics problem involving the law of cosines... etc.  Part of the solution involves selecting the positive root from the resulting 2nd order equation in x(t)- below.  

eq1 := (r1 + r2)^2 = r1^2 + x(t)^2 - 2*r1*x(t)*cos(theta(t))  (law of cosines)

eq2:=diff(eq1,t)

eq3 := subs(diff(x(t), t) = v, diff(theta(t), t) = omega, eq2)  (remove xdot and theta dot)

assume(0 < x(t));
assume(0 < t);
assume(0 < theta(t) and theta(t) < 2*Pi);

xx := solve(eq3, v)  (creates an relationship between v, theta and x)

     xx := -r1*x(t~)*omega*sin(theta(t~))/(-cos(theta(t~))*r1 + x(t~))

Not clear what this t~ notation means?

when I solve eq1 above for x(t) there are two roots.  I select the positve root, but receive this warning...

eqx := solve(eq1, x(t))[1]

Warning, solve may be ignoring assumptions on the input variables.
        eqx := cos(theta(t))*r1 + sqrt(cos(theta(t))^2*r1^2 + 2*r1*r2 + r2^2)

How can I correct or address the warning message?

Finally,  to piece together the solution I perform this step

v := subs(x(t) = eqx, xx)

The result has a fairly obvious "simplification", but using "simplify" and "combine" only makes it worse...  Is there a combination of commands to accomplish a simplification.

Here is the entirety of the Maple...

restart;
with(Typesetting);
Settings(typesetdot = true);

eq1 := (r1 + r2)^2 = r1^2 + x(t)^2 - 2*r1*x(t)*cos(theta(t));
eq2 := diff(eq1, t);
eq3 := subs(diff(x(t), t) = v, diff(theta(t), t) = omega, eq2);
assume(0 < x(t));
assume(0 < t);
assume(0 < theta(t) and theta(t) < 2*Pi);
xx := solve(eq3, v);
eqx := solve(eq1, x(t))[1];
v := subs(x(t) = eqx, xx);

examine the result for v... easy to see the "simpificaion"... but not sure how to manipulate Maple to accomplish this...

JD

So my file got corrupted, i have no clue how to fix it. The file i was able to restore from OneDrive is 2 days old and is missing most of the information, i only have the backup files for the later version. Is there someone with expertice who can help me out? 

Hi everyone!

I'm double checking a result from maple.  When I substitute maple's solution into the differential equation, left side does no equal right side.  Does anyone have some insight into this?

thanks

the maple file is below

is_this_correct.mw

For a system of 8 equations, it takes too long for me to solve it by using solve, but I can only give one solution by using fsolve. If I want solutions in other ranges, I need to provide a general range, but I don't know the range, how can I quickly find all the solutions?question1118.mw

I’m working on deriving the equation of motion (16) from equation (9) (see attached image), but I’ve encountered a couple of issues in Maple. i) The variational derivative of Lagrangian, and ii) the commutator is zero, which isn’t expected.

How do we fix these issues? Are there any specific packages regarding the construction of Lagrangian?

VariationDerivative.mw

How do you convert this system of equations into matrix form? The decoupling process is performed.Convert the equations into photographs.fuxian1030.mw