Answer:
π
The desired formula is y = 3cos(----- t) + 5
5
Explanation:
From maximum point to minimum point, the change in x is 5 and the change in y (min to mx) is (8 - 2), or 6. The graph repeats itself beginning at x = 6 and thus has period 10 (e. g., from first max to next max).
2π
Period and frequency are related through period = ------
b
and so if the period is 10 (as it is here),
2π 2π π
period = 10 = ------------ Therefore, b = ------- = -------
b 10 5
π
The desired formula is y = 3cos(----- t) + 5
5
3 is the amplitude and 5 is the vertical offset from y = 0.