The water depth in a harbour is 21m at high tide and 11m at low tide. One cycle is completed approximately every 12 hrs.
Find an equation.
The Attempt at a Solution
The answer to this problem is y = 5sin 30 (t-3) + 16
A = (M - m) / 2
= (21-11) / 2
C = (M+m) / 2
Period is 12 hrs.
K value would be 30 because 360 / 12.
But I don't know why it is (t-3) I'm not sure where that came from.