q|Np(s)| and |N0(s)| are both small for some
s. That is, |Np(s)|»0 (i.e.,
s is close to a right-half
plane pole of P)
and |N0(s)|»0 (i.e., |P(jw)| is small around w=|s|=r).
q This is possible if |P(jw)| is small around w=r where r is the modulus of a right-half plane pole of P (See Example 16.3)
q|N0(s)| and |M0(s)| are both small for some s. That is, |N0(s)|»0 (i.e., |P(jw)| is small around w=|s|=r) and |M0(s)|»0 (i.e., |P(jw)| is large around w=|s|=r).
q The only way in which |P(jw)| can be both small and
large at frequencies near w=r is that |P(jw)| is approximately equal to 1 and the absolute value of the
slope of |P(jw)| is large. (See Example 16.4)
q
•