This sketch shows how we can create a function for sine and cosine.[br][br]As a point goes around the unit circle, we can see how the different ratios change based on the angle, given here as [math]x[/math] and measured in radians.[br][br]First, select Sine and then Animate. At each of the points on the traced out curve, the x-coordinate represents the angle and the y-coordinate represents the sine of the angle.[br]Notice that the y-coordinates of [math]P[/math] and the point we are tracing are always the same.[br][br]In this way, we can see how to graph the function:[br][math]f\left(x\right)=\sin x[/math][br][br]Cosine can be similarly graphed, but here we are plotting the [math]x[/math]-coordinate of [math]P[/math] for each angle [math]x[/math].