Answer:
The required function is
.
The rider is 50ft above the ground at x=45.56.
Step-by-step explanation:
The general cosine function is
.... (1)
where, |A| altitude,
is period, C/B is phase shift and D is midline.
The center of the wheel is 30ft above the ground. So, D=30.
A Ferris wheel 50ft in diameter makes one revolution every 2 minutes.

Minimum value = 30-25 = 5
It means the equation passes through the point (0,5) and phase shift is 0.



Substitute A=-25, B=π, C=0 and D=30 in equation (1).


Therefore, the required function is
.
Substitute y=50 to find the value of x.



Divide both sides by -25.




Divide both sides by π.



Therefore, the rider is 50ft above the ground at x=45.56.