Does Maple have a function which finds the domain of its variables such that the function is real valued?

I am only interested in a function of two variables, x and y.  I'd like to know what is the range of x and y, where f(x,y) is real valued.

For example, given f(x,y)= x * ln(y), then the domain is all of x, and for y>0.    So it is the upper half plane.  For f(x,y)=sin(x)*cos(y), then it is the whole plane (all x and all y) and so on. 

I looked at singular(), and this does part of what I want, but it only gives me the singular points. So for the above it gives y=0 and x=x, but I am looking for something a little more specific. I also looked at package called RealDomain, but I do not see how to use this for what I want to do. But I could have missed something.

I do not know what the function is beforehand, but it will always be a function of x and y, and I need an automated way to determine the range of x and y where this function is real valued. 

I can't do plots and look at them, since this is all automated and has to be done algorithmically only and non-interactive.

I could use singular, and try evaluating the function at different points and see if it produces real or complex values, but this is not practial to do and can fail.

Does Maple have support for such functionality?

is there example data that can verify maxwell equations?

trig_interp3.mw

Hi all

I have this type of generalized Fourier serie: a0+Sum(an*cos(n*Pi*ln(x)/ln(2))+bn*sin(n*Pi*ln(x)/ln(2)), n = 1 .. N)

The coefficients I calculated and the results seems correct. However, the amplitude of Fourier expansion is twice the amplitude of the function.

Find in the attached file my maple code.

Regards

Dear Users!

Hoped everyone is fine here. I am facing the problem to find the transpose of FDM[1], FDM[2] and FDM[0]. Please see the attachment and fix the mistake. I am waiting your positive respone. 
Help.mw

How to calculate determinant of a cube matrix ?

is there function to calculate 3x 3x 3 cube determinant?

Hellow ,

any body can help me to remove the error from the plot, here is my codes .

Note. 1. *Title {Effect of alpha when 'Gamma2'=Gamma2}

2. *on the y axis i want  bar(deltap)

restart;

h:=z->1-(delta2/2)*(1 + cos(2*(Pi/L1)*(z - d1 - L1))):
K1:=((4/h(z)^4)-(sin(alpha)/Gamma2)-h(z)^2+Nb*h(z)^4):
lambda:=unapply(Int(K1,z=0..1), Gamma2):
L1:=0.2:
d1:=0.2:
alpha:=Pi/6:
plots:-display(Vector[row]([seq(plot([seq(eval(lambda(Gamma2), Nb=j), j=[0.1,0.2,0.3])], delta2=0.02..0.1, legend=[Nb=0.1,Nb=0.2,Nb=0.3],labels = ["d1 ", "Dp"],labelfont = ["SYMBOL", 12], title=(Effect of alpha when 'Gamma2'=Gamma2)), Gamma2=[10,20,30])]),axes=boxed);
 

How to proof classical and quantum both p summation equal to one in maple?

with(linalg):
A := matrix([[1,0],[0,1]]);
AA := exponential(t*A);

A := matrix([[-i/h,0],[0,-i/h]]);
AA := exponential(t*A);
Error, (in evalf/matrixexp) cannot determine if this expression is true or false: 0.9482523555e34*abs(t*i) < 1

arctan(sqrt(3)/2/(1/2));
cos(Pi/3) + i*sin(Pi/3);

exp(i*Pi/3);

cos(Pi/3) + i*sin(Pi/3) - exp(i*Pi/3);

with(ScientificConstants):
Constant(hbar);
h := evalf(%);
dsolve(diff(s(t),t) + i/h*s(t)=0,s(t));
dsolve(diff(s(t),t) + i*s(t)=0,s(t));
 

after solve differential equation, there is no Pi/3, 

can s(t) be a matrix ?

where do Pi/3 come from?

then i try Ket

with(Physics);
K1 := Ket(&psi;t);
dsolve(diff(K1,t) + i/h*K1=0,K1);

Error, invalid neutral operator;
Ket is matrix or complex number ?

and how to solve?

I am still buffled by a Record in Maple.

I simply want to make one variable be a Record. Then make separate variable, by making a COPY of the content of the first variable, then change the second variable. Sounds easy, right?

When I do this, I find that the changes in the second variable are being made also to the first variable.

I used eval() to make a copy of all field of first variable to the second.  May be this is not the correct way, but do not know how else (other by explicit copying one field one at a time).

I looked at help, and see nothing there. It talks about making the Record packed. I tried that, but it is still not working. Not a single example in help of how to copy the "content" of one record to another.

I simply want to make a new instance of the first variable, a copy. and change the second instance without the first changing at same time. Why is this so hard in Maple?

restart;
c:=Record('a','b'):
c:-a:=0:
c:-b:=-1:

c1:=eval(c): #make a copy of c??
print("c1=",eval(c1)); #yes, made a copy

c1:-b:=99:  #change one field  in the second variable

print("c1=",eval(c1));
print("c=",eval(c)); #why did c change?

I tried using Record[packed]('a' , 'b'): since help says something about same Record sharing same memory but that make no difference.

How to make a copy of a record to another in Maple without them being the same? I know I could do this

restart;
c:=Record('a','b'):
c:-a:=0:
c:-b:=-1:

c1:=Record('a','b'):
c1:-a:=c:-a;
c1:-b:=c:-b;

c1:-b:=99:  #change one field  in the second variable

print("c1=",eval(c1));
print("c=",eval(c)); #Now it did not change.

But my actual record has many fields. and I do not want to do the above each time.

aab := int(exp(-a*x)*cos(b*x), x=0..infinity);
simplify(eval(aab));
 

why above equation is not equal to a/(a^2+b^2) ?

and how to solve below equation

z assuming complex;
solve(z^n - z = 0, z);

it only return 1 or 0, but not complex equations in terms of n

I am trying to find formula of the sequence f(n)

f(n+1) = (1+f(n))/(2*f(n)), f(1) = -7/13

I tried
restart;
rsolve({f(1) = -7/13, f(n+1) = (1+f(n))/(2*f(n))}, {f})

But I couldn't get the result. With Mathematica, I got the result.

hi 

i cant comute the double integrate with infinity integral of my function and just evaluating

The calculation steps are too time consuming and will not be answered

Hi, I am very new to Maple and do therefore probably propose a very simple question, so I would kindly ask you to excuse me in advance.

Basically I want so solve a simple and discrete game by comparing expected utility payoffs. There are only three states of the world (0,1,2) and I must determine for what cost-price-ratio what quantitiy is chosen from the same set (0,1,2).

Mathematically it's easy and I solved it, but Maple does not let me present my findings in a way I would like, as presented in my picture (preview from LaTex):

To achieve this I would have to get all w over p and then define it as z (cost-price-ratio). But when I try solving for w/p or respectively z doesn’t work. Additionally, when I try to apply some rearrangements manually (like multiply by 1/p in the first inequality) it doesn't work either, I just receive a '*' in front of round brackets with my equation inside.

So, is there a possibilty to do these simple rearrangement of my inequalities in Maple? And is it possible to aggregate the solutions in the same way as I pictured it for my LaTeX code?

Thank you very much!

Well I also come to think of it, disagree with calling the double factorial function the double factorial function, i would have thought bi-factorial to be better. or singular parity factorial function. 

But my interface (2016)  queries me everytime i enter "n!!" as to whether I am referring to the double factorial function or the application of the factorial twice in iteration, ie :  (n!)!

I just think this was a bad decision to make common place and the notation cabal need to review and change this. 

Hi,

I m trying to work some Maple Formulas in the Excel 2016 environnement, but i m always getting Error Mesages ( See attachments)

Thanks