# Section
2.1 A Trig Graph You’ve Surely Seen

Here is a graph of $y = \sin(x)$, *x* in radians. You’ve surely seen
it many times. In this module, we (meaning us authors) will make sure that
you understand two important things about this graph: what the values of *x*
represent, and what the values of *y* represent.

*Figure 2.1.1. Graph of $y=\sin(x)$*

You might see the graph of $y = \sin(x)$ as just a shape. But the graph
actually represents the behavior of change along a circle. To see this we
must explore the meanings of *y* and *x* in the statement $y =
\sin(x)$.