The depth of the water, d, at the end of a pier changes periodically as a function of time, t, in hours as shown in the graph below. according to the model, the last low tide occurred at 5: 00 a. m. when will the next low tide occur? let t = 0 be 12: 00 a. m.(see attatched file)

a. 3: 00 a. m.
b. 5: 00 a. m.
c. 3: 00 p. m.
d. 5: 00 p. m.

C. 3:00 p.m.
Low tide occurred at 5:00 a.m. (t=5) and the graph shows that high tide occurred at both 12:00 a.m. (t=0) and 10:00 a.m. (t=10).
That means that between high tide and low tide, 5 hours pass (5-0=5 and 10-5=5).
So if the last high tide was at 10:00 a.m., the next low tide will happen another 5 hours later. 5 hours after 10:00 a.m. is 3:00 p.m.

Ibelieve it's a. 2.2 - x = -10.85 (plz tell me if it's right : ) )