Hi,
   I just finished a math quiz. I needed to find the length of the curve and area of the function, r=3*cos(theta)-2*sin(theta) bounded between 0<=Pi<=2*Pi.
   On the quiz I used Area=int(1/2*(r^2)) dtheta. For the length of the curve I used L=int(sqrt(r^2 + r'(theta)) dtheta.

How do you plug this into Maple and get an answer?
I came up with 20.42.... sq units for the area and 22.65.... for the length of the curve.

Thank you,
Jay.

Hi,

I was wondering why when I want to equate



Maple returns

I know that the maple arctan(x,y) (or atan2) plots from Pi/..-Pi/2, but at x = 0, depending on the sign of y, it should either return Pi/2 or -Pi/2. but the equation returned wouldnt do that, It will plot only from Pi/2 to 0. see below.



first, why does maple evaluate it to that particular expression of csgn?
second, how to get a "correct" result?

I cant understend how to use new Maple workbook, and i cant load it on a site so i will use screenshoots to explain. I whant to add my costume functions to code attachments and exceuted them in multitipe workshellds, but i dont know how to excecude them from ther + i cant understend how varibles sistem work. For excemple i go main document ex1, in it i save z as global varible for all worksheed, when i excecute it works alright in other workdoxument c2 but when i change it in main document it didnt change in others, but in saved varibles in ex1 saved new value of z , and in all others z is left same as it was. In such whay i can save function f2 wich is declorated in workdocument c2 as varible, it will exceute in main ex1 but any changes of f2 in c2 wudent be applied in ex2, if i declorated and excecude f1 in c1 code attachment it dont even generate in varibles tables + i dont see any whay to excecute it from ex1, so here the qestion how to excecute functions saved in code attachments in other book's wordsheets and how make saved varibles usable in all book?

Hello! I am facing the problem to making the grahp of system of ODEs in the attached file from eta=-1..1. Please see the attachment and fixed it. I will be waiting your positive response.

new_graph_exact.mw

With my best regards and sincerely.

Muhammad Usman

School of Mathematical Sciences 
Peking University, Beijing, China

Email: muhammadusman@pku.edu.cn

Mob #: 0086-13001903838

There were recently submitted a dozen Maple bugs by me and others. Maplesoft have brought no responses. They keep strategic silence. True merit is not afraid of criticism.

Download Bug_in_Statistics_PDF.mw

Let us consider 

restart; J := int(cos(a*x)^2/(x^2-1), x = -infinity .. infinity, CPV);
-(1/4)*Pi*sin(2*a)*csgn(I*a)-(1/4)*Pi*sin(2*a)*csgn(I/a)

This result is not true for a=I:

eval(J, a = I);
                               0

In this case the integral under consideration diverges because of 

cos(I*x)^2;
                                
                            cosh(x) ^2

i got 3 diff ecuations with two algebraic ones. a system of DAEs. there is only a derivative included on systems, for which it's necesary only one initial condition for solving the system, which is Q(0)=0. why maple wants to know initial conditions for T_1s. it's not supposed to calculate it itself?
 

Download ecuation_2.mwecuation_2.mw

On some platforms, my editor of choice has become the aptly named Sublime Text. Unfortunately, it does not seem to have built in syntax highlighting for the Maple programming language and so I set out to write some.  In the end, I wrote enough highlighting to keep me sane when looking at Maple source, but it could use a lot more work.  So in case anyone is interested I've put what I have in a Github repository: SublimeTextMaple

If you use Sublime Text, please download it and add your own enhacements and share in turn.

I dont understand how to approach this question, can anyone explain what it means by bessel and myJ?? Ive tried but i cant get the integral to work with the dy?

Dear all

I am trying to solve system of ODEs by TWS command for traveling wave solution, but an error is showing. When I enter sinlge ODE or PDE the command does not show any error. Why it is showing error for system of ODEs ?

Download ODEs.mw

Hi everyone

I would like to unassign all  'user' variables but some of them.
More precisely, if 

• MyVars := anames('user')
• and KeepThese := {...} is some subset (manually constructed) of MyVars

I was thinking to something like
for k in MyVars minus KeepThese  do
   k := 'k'   # or k := unassign('k')
end do;

... which (obviously) does not work as desired because 'k' refers to the variable of name k and not to the variable k represents.

How is it possible to fix this ?

Great thanks in advance

Let us consider 

maximize(int(exp(-x^4), x = k .. 3*k), location);

Error, (in maximize) invalid input: iscont expects its 1st argument, f, to be of type algebraic, but received x = k .. 3*k
whereas the expected output is 

[(2*((1/40)*GAMMA(1/4, (1/80)*ln(3))*5^(1/4)*ln(3)^(3/4)-(1/40)*GAMMA(1/4, (81/80)*ln(3))*5^(1/4)*ln(3)^(3/4)))*5^(3/4)*(1/ln(3))^(3/4), [k = (1/10)*10^(3/4)*ln(3)^(1/4)]]

as Mma 11 produces. The following 

RealDomain:-solve(diff(int(exp(-x^4), x = k .. 3*k), k));
  -(1/10)*5^(3/4)*ln(3)^(1/4), (1/10)*5^(3/4)*ln(3)^(1/4)

is not a workaround because of 

int(exp(-x^4), x = (1/10)*5^(3/4)*ln(3)^(1/4) .. (3/10)*5^(3/4)*ln(3)^(1/4));
  FAIL

Hello,

I try to retrieve some procedures from a package that I have in a 2D output.

But, when I copy/paste in a 1D maple input or a simple text file, the main part of the procedure is replaced by "...".

Example :

Package:-procedure
proc(a, b)  ...  end;

Do you have a idea to suppress this feature ? and so that I can retrieve the desired procedures?

Thanks a lot for your help

how to find roots of equation J0(xR) = 0 ,R is constant, using maple? I know command for zeros of Bessel function i.e J0(x) = 0.  but what to do with different argument?

How do I make find and replace work?  Currently the replace and find button is grayed out.  What magic gets me into a state where the button can be used?

Thanks

P.S. Is there any "package" or "mode" or way some how that emacs key bindings can be made to work (including things like find and replace)?  The user interface would be much improved if I knew how to enable that.