A portion of the path of a certain roller coaster can be modeled
by f(t) = t4 - 31t³ + 308t2 - 1100t + 1200 where t represents the time in seconds and
f(t) represents the height of the roller coaster. Use the Rational Zero Theorem to
determine the four times at which the roller coaster is at ground level.
Rational Zero Theorem