Question

The depth of the water at the end of a pier changes periodically along with the movement of tides. On a particular day, low tides occur at 12:00 am and 12:30 pm, with a depth of 2.5 m, while high tides occur at 6:15 am and 6:45 pm, with a depth of 5.5 m. Let t = 0 be 12:00 am.

Graph the equation d = -1.5cos(4pi/25t) + 4 that models the situation using a graphing calculator and use it to answer the following questions.

At approximately what time on the next day does the depth first reach 4 meters?
3:00 am
4:00 am
5:00 pm
10:00 am

Answer 1

I can conform the answer is 4:00am

Explanation:

The guy above explains it

Answer 2

4am is the correct ANSWER

Explanation: