For a rational matrix function Φ with poles outside the unit circle, we estimate the degree of the unique superoptimal approximation 𝒜Φ by matrix functions analytic in the unit disk. We obtain sharp ...

How an input series enters the model is called its transfer function. Thus, ARIMA models with input series are sometimes referred to as transfer function models. In the preceding regression and ...

All quadratic functions have the same type of curved graphs with a line of symmetry. The graph of the quadratic function \(y = ax^2 + bx + c \) has a minimum turning point when \(a \textgreater 0 \) ...