You haven't defined A anywhere in the problem statement. The only thing that makes sense to me is that A is an N x N matrix. But the stated convergence property would only be true for certain A, those with spectral radius less than 1.

@hillyzz Copying the code is fine, but it is incomplete. I need the values of k_min, k_max, n0, n1, and n2. Also, what is the procedure multiply? Do you just mean to multiply the Matrices? That can be done as P1p.F1p.P2p.F2p.

@DJJerome1976 For some values of theta, filled is interpretted as the area between the curve and the x axis. It ignores the fact that it is polar coordinates.

@Preben Alsholm It seems that the option filled= true doesn't do anything when used with animatecurve.

Please do not edit a Question, making substantial changes, after the Question has been Answered! If you do, then the Answers don't make sense.

The original question was to find the Fourier series for x^2 on -Pi..Pi and to evaluate this at x= Pi to prove that Sum(1/n^2, n= 1..infinity) = Pi^2/6.

@mahmood180 

Mahmood,

Please note my correction to Mehdi's Answer. You need to change nops(C) to numelems(C). The nops is only using the first three of the five constraints. This causes a small change in the final answer.

Please post a more-detailed example. Certainly the information can be extracted from the plot data, if need be. Generally (there are some exceptions), one can extract the data matrix from a plot like this:

plot(...);
P:= %:
M:= op([1,1], P);

Then M is a matrix of two columns, the first being the x values and the second being the y values.

More sophisticated solving techniques may be possible also.

@mehdi jafari

Mehdi,

You correctly indentified the source of the error as the {C=0} in the line

However, your correction

is not quite correct. You cannot correctly apply nops to a Vector. You need to use numelems instead. nops(C) returns 3, whereas the correct number of elements is 5. This makes a small change in the optimal point.

@acer It doesn't work for me. I get this error message:

Error, (in dsolve/numeric/SC/preproc) unable to compile (rc=1), please try again, and if that fails verify your Windows compiler installation

I am using the default Maple 18 compiler, which seems to work for me in other cases.

Using Maple 18/64 on Windows 8.1/64.

Does the compile option work for you on this ODE system?

@J4James Where did you get that piecewise expression? I don't think that you can use that. As far as I can tell, this sum is not the Fourier series of a piecewise constant function. As far as I can tell, it is the Fourier series of 2*ln((1+sin(2*Pi*x))/(1-sin(2*Pi*x))).

@victormath19 You need to re-execute the code. The execution of the dsolve and the animation command must be in the same "session". When you re-open a worksheet, the results of prior computations are not accessible, even though they may be displayed.

@victormath19 I put my code after yours, and it works fine; although I think it's better without constrained scaling.

@victormath19 You need the set the values of TempsInitial and TempsFinal. Since those names were used in your original code, I assumed that they were already defined. You have to call dsolve also, and equate its output to Trajectoire.

Also, are you mistakenly failing to include the z values in your plot?

@Preben Alsholm I assumed (in my Answer below) that Trajectoire was the output of a dsolve(..., numeric) call.

@J4James If you change k to a float value other than 1, then the integrand becomes complex. In particular, it contains the subexpression (Q-1)^(1/k), a negative number raised to a fractional power.