In shadow bay in july, high tide is at 1: 30 pm. the water level is 4 feet at high tide and 0 feet at low tide. assuming the next high tide is exactly 12 hours later and the height of the water can be modeled by a cosine curve, find an equation for shadow bay's water level in july as a function of time (t).
f(t) = 2 cos pi over 6 t + 1
f(t) = 2 cos pi over 6 t + 2
f(t) = 4 cos pi over 2 t + 1
f(t) = 4 cos pi over 2 t + 2