FAQ: In Example 5.3, why is the A matrix in the given form?
From FBSwiki
(Contributed by R. M. Murray, 5 Apr 08)
In Example 5.3, we consider the state space representation of the model
If we choose the state vector to be 
then the dynamics matrix for the system is given by
which is different than the form listed. Instead, we can use a normalized set of coordinates
A similiar form can also be obtained by rescaling time by 
, as described in Example 2.6.
