Sigma sum error (Unrecognized variable n)

I'm trying to plot this complicated graph using matlab.

[Ghazwan]

Well, you need to define n in the functions. You can do a for loop then you may have the summation.

Answer 1

[KSSV]

Something like this:

clear ; clc ;

thesum = 0 ;
for n = 1:10
    a = @(x) ((-0.07305.*x.^5+2.813.*x.^4-39.78.*x.^3+249.5.*x.^2-640.5.*x+1073).*cos(n*pi.*x/6)./6);
    b = @(x) ((-0.07305.*x.^5+2.813.*x.^4-39.78.*x.^3+249.5.*x.^2-640.5.*x+1073).*sin(n*pi.*x/6)./6);

    c = integral(a,-6,6) ;
    d = integral(b,-6,6) ;
    % e = c.*cos(n*pi.*x./6)+d.*sin(n*pi.*x./6)
    thesum = thesum+c+d  ;% +4796.1296
end