Problem: Investigate the oscillating chemical reaction equations discussed in class for positive values of the parameters a and b:

x' = -x + a -4xy/(1 + x2)
y' = bx(1 - y/(1 + x2)

You should restrict attention to 0 < a, b < 20. In particular, paint the picture of the a,b plane indicating where the reaction tends to equilibrium and where it tends to oscillate.