### Video Transcript

What function is being represented on the graph?

On our graph, we can see that the ๐ฅ-values are in terms of ๐: ๐ over two, ๐, three ๐ over two, two ๐. And then, ๐ฆ are the real numbers.

So letโs think about the values on the unit circle. We begin at zero and then go counterclockwise. And weโre at ๐ over two and then weโre at ๐ and then three ๐ over two and then a full circle all the way around; that would be two ๐. So at zero, we have the value of zero; at ๐ over two, weโve the value of one; at ๐, weโre at zero; at three ๐ over two, weโre at negative one; and then at two ๐, weโre at zero again just like at zero.

So these values we can recognize from the unit circle. Weโre at one, zero and next weโre at zero, one. And then here, weโre at negative one, zero, and here weโre at zero, negative one. So these are all ๐ฅ๐ฆ values. And the values that are on our graph are the ๐ฆ-values in pink.

So if we remember, the ๐ฅ-values represent the cosine function and the ๐ฆ-values represent the sine function. So that means our graph must be the sine function.