Question

In Pensacola in June, high tide was at noon. The water level at high tide was 12 feet and 2 feet at low tide. Assuming the next high tide is exactly 12 hours later and that the height of the water can be modeled by a cosine curve, find an equation for water level in June for Pensacola as a function of time (t).

Answer 1

f(t) = 12 cospi over 2t + 5

f(t) = 5 cospi over 2t + 12

f(t) = 5 cospi over 6t + 7

f(t) = 7 cospi over 6t + 12

Answer 2

@cp9454

Answer 3

high tide = 12 feet
low tide = 2 feet

so, peak to peak = 12-2 = 10
amplitude = 10/2 = 5

Answer 4

In light of above information, which two options can you eliminate ?

Answer 5

C and..... @ganeshie8

Answer 6

B?

Answer 7

do you mean, the answer is betwee B and C ?

Answer 8

I guess lol

Answer 9

then you're correct :) it is between B and C

Answer 10

`the next high tide is exactly 12 hours later `

that means, period = 12

Answer 11

whats the period of cosine function in option B ?

Answer 12

12?

Answer 13

how ?

Answer 14

I guessed, cause the last number is 12 in their equation

Answer 15

haha thats a very good guess, but the last number does not represent period - it represents the vertical shift

Answer 16

so then how would I figure out what the period of cosine function is?

Answer 17

\[\large y = A\cos(Bt ) + C\]

period = \(\large \dfrac{2\pi}{B}\)

Answer 18

Answer is C

Answer 19

Yep !