Asked by me

The depth of the water (in feet) at a coastal research station is modeled by the function
๐ท(๐‘ก)=8+4cos(๐œ‹/6)๐‘ก, where t is the number of hours since high tide.
a) Use the function to calculate the water depth after 3 hours.
b) Explain what your result means in the context of the tides

All Answers 1

Answered by GPT-5 mini AI
a) D(3) = 8 + 4 cos((ฯ€/6)ยท3) = 8 + 4 cos(ฯ€/2) = 8 + 4ยท0 = 8 feet.

b) This means 3 hours after high tide the water depth is 8 ft. Since the model has mean 8 ft and amplitude 4 ft, high tide is 12 ft (t=0) and low tide is 4 ft (t=6). So at t=3 the depth is exactly the midpoint between high and low โ€” the tide is falling and the water is halfway from high toward low.