[填空题]
The tides at the Porkf/q+lq, m 2imosl xj.dl.9 ccvgv)rz6 5p /7lt of Bristol, UK, were observed by a student.
On a particular day, the range between the lowest and highest tides is 10.6 m and the time difference between high tides is 12.2 hours. The first highest tide occurs at 8:12 am and is 12.5 m high.
The height, H, in metres, of the tides can be modelled by the equation
H=asin(b(t−c))+d,0≤t≤24,where t is the elapsed time, in hours, since midnight.
1.Write down the value of:
(1)a;
(2)d.
2.Find the value of b. ≈
3.Find the smallest possible value of c, given c>0. ≈
4.Hence draw the graph of H versus t, for 0≤t≤24.
