A simple model of the human heart beat gives
where is the displacement from equilibrium of the muscle fiber, is the concentration of a chemical control, and A are positive constants. Assume , A = 3.
a) Calculate and for starting with
, . Use ``xmgr'' to plot the output in the phase
plane (x along the horizontal axis, c on the vertical). What does
the period appear to be?
b) Repeat with , .