Final answer:
The sine function should be graphed to model the rider's motion on the Ferris wheel because it accurately represents the periodic oscillation of the rider moving from the top to the bottom and back to the top.
Step-by-step explanation:
The sinusoid that should be graphed to model the ride of your chosen rider on the Ferris wheel is the sine function.
A sine function is appropriate because the rider starts at the top of the Ferris wheel, moves down to the bottom, and then returns back to the top. This motion can be represented by the periodic oscillation of the sine function.
The sine function oscillates between +1 and -1 every 2 radians, which corresponds to one full revolution of the Ferris wheel. Therefore, graphing a sine function with the appropriate amplitude and period will accurately model the rider's motion on the Ferris wheel.