As Ricky rides his rocking horse, the distance from the horse's tail to the ground, in centimetres,in terms of seconds, is modelled by the equation

d(s) = 2sin(720s)+20.

1. a)How long does it take for the tail to go all the way up and all the way down once?
2. b)How high off the ground is horse's tail from the ground when it is at the maximum?

c)How high off the ground is horse's tail from the ground when it is at the minimum?