For fixed z and a=9/2, b>=a
For fixed z and a=9/2, b=37/8
For fixed z and a=9/2, b=39/8
For fixed z and a=9/2, b=41/8
For fixed z and a=9/2, b=43/8
For fixed z and a=9/2, b=45/8
For fixed z and a=9/2, b=47/8