Hi guys.

           if an expression complicated as the following,  

sqrt(sqrt(9)*sqrt((1+(b+1)^2*c^2+((10/3)*b-2)*c)*(1+(b+1)^2*c^2+(2*b-2)*c))+3+(3*b^2+6*b+3)*c^2+(8*b-6)*c) , where b>0 c>0

is it possible to tell whether it could be positive? 

I used coulditbe command, however, it returned 'FAIL'.

Having a function where the value is for example only defined when abs(x) <= 1, then how can I specify that the value is otherwise undefined, the replacing "How_to_specify_undefined_value" below?

It would be nice if the StringTools package had a function giving the number of primitive words of length n on an alphabet of size a.  The formula for this is well-known but tedious to code.

I am using Maple 2015.2 on a Windows 10 machine.  I use the plot command to generate a simple graph.  I then use the Manipulator Pan tool to change the axes limits.  The system does not redraw the function with the new range limits.  The parameters in the Axis properties have been changed appropriately but the graph does not display for the new limits.  Even if I change the parameters without using Manipulator Pan tool, the system does not redraw the function with the new range limits.  Any guidance about what I am doing wrong?  I am attaching an example file in case the behavior continues on other systems.

20160711_example_of_graph_pan_issue.mw

Thanks,

Wayne

Dear All

It is well known that the package "PDEtools" is helpful in finding infinitesimal transformations for PDEs which I illustrate as follow:

Download Writing_Vector_fields.mw

Regards

        General description of the method of solving underdetermined systems of equations. As a particular application of the idea proposed a universal method  kinematic analysis for all kinds of  spatial and planar link mechanisms with any number degrees of freedom.  The method can be used for powerful CAD linkages.   
         http://www.maplesoft.com/applications/view.aspx?SID=154228

       

      Some examples of a much larger number calculated by the proposed method. Examples gathered here not to look for them on the forum and opportunity to demonstrate the method.  Among the examples, I think, there are very complicated.

https://vk.com/doc242471809_408704758
https://vk.com/doc242471809_408704572
https://vk.com/doc242471809_376439263
https://vk.com/doc242471809_402619761
https://vk.com/doc242471809_402610228
https://vk.com/doc242471809_401188803
https://vk.com/doc242471809_400465891
https://vk.com/doc242471809_400711315
https://vk.com/doc242471809_387358164
https://vk.com/doc242471809_380837279
https://vk.com/doc242471809_379935473
https://vk.com/doc242471809_380217387
https://vk.com/doc242471809_363266817
https://vk.com/doc242471809_353980472
https://vk.com/doc242471809_375452868
https://vk.com/doc242471809_353988163 
https://vk.com/doc242471809_353986884 
https://vk.com/doc242471809_353987119
https://vk.com/doc242471809_324249241
https://vk.com/doc242471809_324102889
https://vk.com/doc242471809_322219275
https://vk.com/doc242471809_437298137
https://vk.com/doc242471809_437308238
https://vk.com/doc242471809_437308241
https://vk.com/doc242471809_437308243
https://vk.com/doc242471809_437308245
https://vk.com/doc242471809_437308246
https://vk.com/doc242471809_437401651
https://vk.com/doc242471809_437664558

I am having 26th degree polynomial univariate equation , I used Isolate to get the roots. but I am getting some extra roots which are not true they I even tried to substitute those roots in original equation then I got non zero answer instead of getting nearly zero answer.How is it possible??

equation looks like:

-12116320194738194778134937600000000*t^26+167589596741213731838990745600000000*t^24+1058345691529498270472972795904000000*t^22-4276605572538658673086219419648000000*t^20-23240154739806540070988490473472000000*t^18-5442849111209103187871341215744000000*t^16+49009931453396028716875310432256000000*t^14+74247033158233643322704589225984000000*t^12-2762178990802317464801412907008000000*t^10-25947900993773120244883450232832000000*t^8-7468990043547273070742668836864000000*t^6-567730116675454293925108383744000000*t^4+3703566799705707258760396800000000*t^2-4742330812072533924249600000000

Solutions i got:

[t = -4.162501845, t = -2.295186769, t = -1.300314688, t = -.8048430445, t = -0.6596008501e-1, t = -0.4212510777e-1, t = 0.4212510777e-1, t = 0.6596008501e-1, t = .8048430445, t = 1.300314688, t = 2.295186769, t = 4.162501845]

t=4.162501845 give me non zero answer when I substitute it in the equation given above:

I got this answer: 4.750212083*10^39

Hi there,

            Recently, I encountered a problem. I have a function( omega as its variable)  (18)

 gamma*sqrt(4)*sqrt(omega^2*C2^2*R4^2/(C2^4*R4^4*beta^2*gamma^2*omega^4+C2^2*(1+gamma^2*(beta+1)^2-2*gamma)*R4^2*omega^2+1))

I tried to find a point where its first derivative equals 0. In this case, Maple returned four solutions. In my

question, both beta, gamma, R4 and C2 >0， I want it to return a real positive solution, the first term

in (19) (i.e. 1/(sqrt(beta *gamma) *1/R4 C2).

I know it is easy to find out the positive real roots in this case. This question seems to make no sense.

However, sometime I came across an expression complicated enough that I cannot tell whether it is real

positive.

Is there a approach to find a real positive solution of an symbolic eqution?

Thanks in advance!

                                                                     A University student in BeiHang University, Beijing

I'm trying to call a C function which returns an array. The example on the help page http://www.maplesoft.com/support/help/maple/view.aspx?path=examples/ExternalCalling is to pass in an array with known dimensions, which will be updated in the C function, but I wonder if this is the only way to do it. For example if I have an array of unknown dimensions beforehand, what is the best approach to return this array?

Thanks!

I am trying to solve a matrix system to find the relative arrival rates of a queueing network using Gauss-Seidel.The maple commands are below:

restart;
with(Student[NumericalAnalysis]); with(LinearAlgebra);

A := Matrix([[1, -.333, -.333, -.333], [0, 1, -.333, -.333], [0, -.333, 1, -.333], [0, -.333, -.333, 1]]);

IsDefinite(A, 'query' = 'positive_semidefinite');

true

b := Vector([1, 1, 1, 1]);

IterativeApproximate(A, initialapprox = Vector([1, 1, 1, 1]), tolerance = 10^(-3), maxiterations = 20, stoppingcriterion = relative(infinity), method = gaussseidel);

Error, (in Student:-NumericalAnalysis:-IterativeApproximate) check that the augmented matrix has the correct dimensions

I do not understand this error as the matrix is 4x4 as shown. Can anyone see where I went wrong?

 Hello every one,how do i integrate from this expression?

Download integral.mw

Hello,

I have a number of outputs, and I want to put them into an Array witrhout specifying the index of the array, is there a way I can put all of them at once without putting them one by one? I am currently using Append, is there any other way other than Append?

Points on the coordinate plane

(Guidance manual for the 6th class)

Changing the initial coordinates and going through the entire program first, we get a new picture-task

    Point_on_co-plane.mws

And Another     Coordinate_plane.mws

I have Maple 2016 loaded on a MacBook Pro running the El Capitan operating system. What is the keyboard button sequence for typing a Greek letter?

Thanks

Tom

Coordinate axis

6th class (in Russia)

Guidance manual for use at lessons (at school)

Coordinate_line_lesson.mws

(It is possible bad English)