Answer:
D (I think)
Step-by-step explanation:
I used a right triangle calculator and that was the answer
Below is the process the calculator did, hope it helps.


Draw a diagram to illustrate the problem as shown in the figure below.
The minimum depth of 2.5 m occurs at 12:00 am and at 12:30 pm.
Therefore the period i0s T= 12.5 hours.
The maximum depth of 5.5 m occurs at 6:15 am and at 6:45 pm. Therefore the period of T = 12.5 hours is confirmed.
The double amplitude is 5.5 - 2.5 = 3 m, therefore the amplitude is a = 1.5 m.
The mean depth is k = (2.5 + 5.5)/2 = 4.0 m
The model for tide depth is

That is,
d = -1.5 cos(0.5027t) + 4
where
d = depth, m
t = time, hours
A plot of the function confirms that the model is correct.
Answer:
Steps For Solving Real World Problems
2. Highlight the important information in the problem that will help write two equations.
3. Define your variables.
4. Write two equations.
5. Use one of the methods for solving systems of equations to solve.
6. Check your answers by substituting your ordered pair into the original equations.
Answer:
Yes; she will have $4008 for other expenses.
Step-by-step explanation:
First you find out how much she saved by multiplying 350 by 36 as she saved for 3 years which is 36 months.

After that you need to work out the amount she needs in total for her tuition by multiplying 4 by 3723 which is the amount needed per year.

If her parents add to her account half the amount she saved that means that they give her an additional 6300 as that's half of 12600.
This means she has 18900 and if you take away 14892 you will be left with 4008 for expenses.
21.325 is the correct answer