% ex05

N=64; n=[0:N-1]; k=n;
x=0.5.^n;
Y=1./(1-0.5*exp(-1j*2*pi/N*k));
y=real(ifft(Y));
stem(n,y); title('y[n]'); pause
my=x/(1-0.5^N);
hold on
stem(n,my,'m')
hold off
title('my[n]'); pause
stem(my-y)
title('my[n]-y[n]');