Classic Fourier Series

[Han]

(01-30-2015 09:06 PM)salvomic Wrote:  

(01-30-2015 07:54 PM)Han Wrote:  If you look at how a(f,k) was defined, the f is assumed to be a CAS function (notice the f(t) reference in how a(f,k) is defined). This means you need to pass a CAS function.

f(t):=t^2;
a(f,1);

in this way it works (I used also variant with Int(...,0, 2π) ), but I tried this:
create a0 (first term), ak, bk variable with expressions
f(t):=|sin(t)|
I got warning about the absolute value...
then I got value for a0 (as a0:=(1/2π)Int(f(t),t,0,2π)
After this value for a0, ak, bk and also f=f(t) are reset and I must rewrite all three functions...
There is a reason? Is is possible to maintain the function

Perhaps is better a little program that give a list with (a0, ak, bk)?

I'm not sure I understand what you did; perhaps you could copy/paste the actual commands you used? I am not having any trouble with respect to things "disappearing"