Translations:Magnitude spectrum and phase spectrum/8/en

Because both the input vector at time n and the output vector at time n make the same angle with the horizontal axis, we say that the input and output are in phase. Here, we have assumed tacitly that $b_{0}$ is a positive constant. If, on the other hand, $b_{0}$ is a real positive constant, say, $b_{0}=-{0.5}$, we have the situation shown in Figure 3.