Some definition of n! where n are the negative integers is taken to be infinity. (this is Gamma function for negative integers).

https://en.wikipedia.org/wiki/Gamma_function

So 1/(-1)!  should be zero. And that is what Mathematica gives

But Maple does not like (-1)!, it gives division by zero, I assume because it is not using the above definition using Gamma function.  But then how come Maple is able to find correctly this sum

sum(1/factorial(n-1),n=0..infinity)

Which is exp(1).   The first term above, when n=0 is   1/(-1)!  which Maple does not like. Because if we take the first term as 1/infinity=0 then the sum is the same as if we had

sum(1/factorial(n-1),n=1..infinity)

And now it is exp(1) with no problem dealing with negative integer factorial.

Question is: Since Maple does not like negative integer factorial, how comes it accepted the above sum, whose first term contain negative integer factorial? 

Just wondering how it did the above, that is all. When I solved this by hand, I used 1/(-1)! = 0 to be able to sum it.

I have converted a single large worksheet into a workbook comprising many worksheets.  One of the worksheets contains start-up code.  Is that start-up code (which includes numerous subroutines/functions) automatically available/accessible/executable by all the other worksheets in the workbook?  

Melvin

I have this animation that displays a particle's position after reflection from a shock (the blue plane). I want to add a line that shows the particle coming in and reflecting and have them animate sequentially, but I cannot figure out how. The line should travel along the b axis, but offset in the xi axis to end where the helix begins. Here is the code for the helix animation:

restart; with(VectorCalculus); with(Student[LinearAlgebra]); with(plots);
v[i] := 145000; thetabn := (1/8)*Pi; thetavn := (1/6)*Pi; k := 10; omegac := .5;
v[b] := cos(2*thetabn)/cos(thetabn); v[g] := sin(2*thetabn)/cos(thetabn);
n := `<,>`(k*cos(thetabn), k*sin(thetabn), 0);
vr:=
[v[b]*t, v[g]*sin(omegac*t)/omegac, v[g]*cos(omegac*t)/omegac];

lambda := v[i]*cos(thetavn)/cos(thetabn);
shockplot := PlanePlot(n, caption = "", planeoptions = [colour = blue, transparency = .5], normaloptions = [shape = cylindrical_arrow, colour = red]);

t1 := textplot3d([k*cos(thetabn), k*sin(thetabn), 0, 'n'], align = above);

display(plots[animate](plot3d, [[v[b]*t, v[g]*sin(omegac*t)/omegac, v[g]*cos(omegac*t)/omegac], t = 0 .. x], x = 0 .. 6*Pi, axes = normal, colour = red, labels = ["b", zeta, xi], thickness = 2, paraminfo = false), shockplot, t1, scaling = constrained, tickmarks = [0, 0, 0]);

Hello pdsolve experts:  

Using Maple 2018.2.1 and Physics 292 on windows 10.

pde := diff(w(x,y),x)+ (arccot(x)^n *y^2 + y-  arccot(x)^n )*diff(w(x,y),y) = 0;
pdsolve(pde,w(x,y));

When I try

PDEtools:-charstrip(pde,w(x,y))

It does not generate error.

Should pdsolve have generated this error message instead of returning no solution?

Hello my friends

I want to solve first order non-linear differential equation by maple 2018 but it does not give me the explicit form for a(t) as the function of time t.

this is my equation where z,k,c, and w are non zero constants 

3*a(t)-a(t)^2-3*z*(diff(a(t), t))^2+k*c*a(t)+w/a(t) = 0

please guide me.

with the best regard

Hi

I would like to designate AU as currency for my application, rather than the USD.

I can do it to a degree, but when I use combine I have problems. Compare output 8 and 9 to 17 and 18. help?

CURRENCY.mw

Download light.mw

Hello,

I'm a long-time Maple user and have used the CodeGeneration package in the past, but with a recent download of Maple 2018, I'm now getting an error I have never gotten before. Even when I do something simple (see below, for example), I get an error that reads "Error, (in clear) argument `` is incorrect or out of order". And I get this error no matter which language I choose. Any help would be much appreciated.

> with(CodeGeneration)

> R(exp(x))

Thanks!

I hope you can help me. I like to use the Workbook feature in Maple 2018. I save variables in one document to use them in another document as well. If, however, the value of the variable changes, I have to delete the variable in the variable manager each time and save it again.
Is there a command I can use to delete and re-save the saved variables?

Hey,

I have just started using Maple for my university project and I am follwing this guide https://www.maplesoft.com/support/help/maple/view.aspx?path=DifferentialGeometry%2FTensor%2FKillingVectors to calculate Killing Vectors. My issue is that when I try and define a metric using evalDG, I need to write dx&tdx to mean the tensor product between the two. Maple interperates this as a neutral operator and gives me "Error, invalid neutral operator".

I am not sure where the issue is as I have written exactly the same code as the guide and yet it gives me an error 3 lines in. Is there some issue that I am not aware of as someone who hasn't used Maple before? Any advice would be useful as I am not really sure how it is possible and I need to be able to write the tensor product to define the metric. 

Even for the simplest metric it does not work. My code is:

with(DifferentialGeometry): with(Tensor): with(LieAlgebras):
DGsetup([x, y], M):
g1:=evalDG( dx&tdx):
 

Any help would be greatly appreciated.

how I can find solutions for non linear equations.

I want to find non zero solution.

thank you

ZAH.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/ZAH.mw .
 

Download ZAH.mw

Hi, Maple is totally new to me and I found something confusing.

Here is what I have:

And it shows Error, invalid input: unknown uses a 1st argument, A (of type Array(numeric)), which is missing.

But in another similar procedure, I have exactly the same lines but it goes without error. 

I have no idea what is wrong with these 4 lines.

Thank you in advance!

I am on a Mac and unable to login to MapleCloud. I can log in perfectly fine via the website in all browsers. Any solutions for this?

How to simplify

a*b=a*c

to b=c ?

I have a procedure that changes the value of an input variable quite unexpectdly. Can anyone explain why? I have a very simplified example of this below.

restart;
with(LinearAlgebra):
switch := proc (V::Vector)
description "This procedure is supposed to take a Vector V and switch entries 1 and 2";
local W,a,b;
W:= V;
a:= W[1];
b:= W[2];
W[1 ] := b;  
W[2] :=a;
W
end proc;

V1:=Vector([1,3,5]);
V2:=switch(V1);
I have omitted the output for brevity's sake but all works well as expected.
However,
V1;

returns V2 not V1. Why is the procedure changing V1?
 

The problem occurs with matrices but not with lists.

Thanks.