That's a typo...if the acceleration of gravity is -16ft/s^2??? Maybe basketball on Mars :P
Free fall equation result from integration of the acceleration equation with respect to time...
a=g
v=gt+v0
h=gt^2/2+v0t+h0 where v0 and h0 are initial velocity and height respectively..
Since acceleration, g, is about -32ft/s^2 not -16ft/s^2 you get:
h=-16t^2+36t+4 for your height equation.
h(2)=12 ft