Answer:
![y=4sin((\pi )/(6) x+(\pi )/(2) )](https://img.qammunity.org/2020/formulas/mathematics/high-school/t292vc9yfe8uya2113vrfis3juhrea8iht.png)
Explanation:
We start from the general form of the sine function which is:
![y=a sin(bx+c)](https://img.qammunity.org/2020/formulas/mathematics/high-school/ypn17j424dnbd3l6fq9rs4530rd5pkfr84.png)
where
Amplitude= IaI=
=4( which is the maximum value we have above the 0 axis)
Period=
![(2\pi )/(b)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gshx709769ka8kugdp5sdpciuvhk0lbuqx.png)
Period=12 (space between high tides)
Isolating b:
![b=(1)/(6) \pi](https://img.qammunity.org/2020/formulas/mathematics/high-school/h5o82aw01j2nohaoge2dbsqw57fcrv0mq9.png)
Horizontal shift = c (Normally the function starts at 0 but in the excercise we have at midnight hight tide this meaning the function is at its maximum value so we need to move it a quarter of the period so it will have maximum value at t=0)
then
![y=4sin((\pi )/(6) x+(\pi )/(2) )](https://img.qammunity.org/2020/formulas/mathematics/high-school/t292vc9yfe8uya2113vrfis3juhrea8iht.png)