My answer:

Question

Y= -82.5 cos (4pi/3)x+91.5
(Period: 1.5=2pi/b --> b= 4pi/3 )

The diameter of the wheel is 165 feet, it rotates at 1.5 revolutions per minute, and the bottom of the wheel is 9 feet above the ground. Find an equation that gives a passenger's height above the ground at any time t during the ride. Assume the passenger starts the ride at the bottom of the wheel.

Answer 1

Looks good to me.

Answer 2

I had done this for you on Tuesday and had verified it for you at the end of the solution

http://www.jiskha.com/display.cgi?id=1374031966