intgration for fi (as part of The Invert Fourier transform

v*=C(1)+C(2)*x+C(3)*x^2+C(4)*x^3

C_orginal =[ 0;

                  -(M0*l*exp(2*fi*i))/(EI*(8*exp(fi*i) + 2*exp(2*fi*i) + 2));
     (M0*exp(fi*i)*(2*exp(fi*i) + 1))/(EI*(8*exp(fi*i) + 2*exp(2*fi*i) + 2));
    -(M0*exp(fi*i)*(exp(fi*i) + 1))/(2*EI*l*(4*exp(fi*i) + exp(2*fi*i) + 1))];

I re-arranged the vector and turned it from symbolic to numeric

i=i

M_0=1

EI=1

L=100

x=0.5*L

N=20

---

for k=-N:N

fi=-pi:pi/900:pi;

C5=M_0/(2*EI);

gama=exp(i*fi);

delta_0=4+2*cos(fi);

C_2= [0 ;

    -C5*L*gama/delta_0;
     C5*(2*gama+1)/delta_0;
    -C5*(gama+1)/(L*delta_0)];

V_befor_int=(x*C_2(2)+(x^2)*C_2(3)+(x^3)*C_2(4))*exp(i*fi*(-k));

V_K_ORIGINAL(k+N+1)=(1/(2*pi))*trapz(fi,real(V_befor_int)); (<__the problam is here)

end;

I get Unreasonable resolt for the integral for fi on the equation :V_K_ORIGINAL

how can i do the interation??

please, see the attached image

tnx for your help

raz