i = 11
a = 99999997952.000000
b = 99999997952.000000
r = 1.000000
r = 1.000000

i = 16
a = 10000000272564224.000000
b = 10000000272564224.000000
r = 1.000000
r = 0.000000

i=11以降aとbの値が変わることと
i=16以降等価でなくなる理由を教えて下さい