$y(\infty)$ and $y(0)$

The general solution allows to easily determine the limiting cases of the zero-rate $y(t) := \ln(-P(t)/t)=(u^\prime(t)\,\xi-v(t))/t$ for $t\to 0$ and $t\to\infty$,

$$\begin{eqnarray*} y(0) &=& \lim_{t\to 0} \frac{u^\prime \xi - v}{t} = e_1^\prim... ...{t} = 0 - \left(a+{1\over 2}V Q b\right)^\prime\,Q\,b \quad . \end{eqnarray*}$$