q*b**opt*(*P**5*) will be small if |*P*5(j*w*)| is small around the
frequency of the modulus of the right-half plane pole.

qFor poles with the same
modulus, *b**opt*(*P**5*) will be smaller for a
plant with relatively larger real part poles than for a plant with relatively larger imaginary part
poles(i.e., a pair of real right-half plane poles has a much worse effect on the
performance than a pair of almost pure imaginary axis right-half
plane poles of the same modulus).