Infamous cat burglar Dogperson (that name is just as legitimate as Catwoman) leaps
from a penthouse window. At first, their fall is modeled by
F(t) = −t² − t +300, where t is the time since they jumped. After a certain
amount of time, they open their parachute, after which, their fall is modeled by
P(t) = -t+284. At how many seconds did Dogperson open their chutes?