The herd of 64 deer is introduced on the small island. At first herd increases rapidly, but ultimately food resources dwindle and population declines. Assume that number N(t) of deer after t years is provided by
N(t) = -t4 + 12t2 + 64, where t 0.
(a) Find the values of t for which N(t) 0
(b) Does population become extinct?