We do not sample the function enough to get an accurate portrayal of the signal. I changed the sample rate to take 25 samples per period. F0 =13; T0 =1/F0; Ts = 1/(F0*25); t = 0:Ts:13*T0; x = real(exp(j*(2*pi*F0*t-pi/2))); plot(t,x)
