# Math Help - What exactly is sine, cosine or tangent?

1. ## What exactly is sine, cosine or tangent?

When we press any of these buttons on any scientific calculator and press enter, we are given a number. As we do this again the number changes. What does it mean exactly? When I first did tried this I thought sine was sort of a bit like pi, but since the number changes it is obviously different. Just to clarify, do these numbers signify points on some sort of continuous curve? Or is it something different?

3. The coordinates of the point on the unit circle (a circle of radius 1) at x degrees is $(\cos x,\sin x)$.