options: Prove and apply trigonometric identities.

Extend the domain of trigonometric functions using the unit circle.

Use functions to model relationships between quantities.

Interpret functions that arise in applications in terms of the context.

Interpret expressions for functions in terms of the situation they model.

Build a function that models a relationship between two quantities.

Model periodic phenomena with trigonometric functions.

Build new functions from existing functions.

Analyze functions using different representations.

Define, evaluate, and compare functions.

Construct and compare linear and exponential models and solve problems.

Understand the concept of a function and use function notation.
problem_activity: Task
A wheel of radius 0.2 meters begins to move along a flat surface so that the center of the wheel moves forward at a constant speed of 2.4 meters per second.  At the moment the wheel begins to turn, a marked point $P$ on the wheel is touching the flat surface.
[IMG]
Write an algebraic expression for the function $y$ that gives the height (in meters) of the point $P$, measured from the flat surface, as a function of $t$, the number of seconds after the wheel begins moving.
Sketch a graph of the function $y$ for $t>0$.  What do you notice about the graph?  Explain your observations in terms of the real-world context given in this problem.
We define the horizontal position of the point $P$ to be the number of meters the point has traveled forward from its starting position, disregarding any vertical movement the point has made.  Write an algebraic expression for the function $x$ that gives the horizontal position (in meters) of the point $P$ as a function of $t$, the number of seconds after the wheel begins moving.
Sketch a graph of the function $x$ for $t>0.$  Is there a time when the point $P$ is moving backwards?  Use your graph to justify your answer.


correct_option_index: 3

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