Unit circle

The unit circle is the circle around the origin of a coordinate system with radius $r=1$. This means it represents the set of all points that have a distance of $1$ from the origin.

For example, the points

• $(1 ~|~ 0)$

• $(0 ~|~ 1)$

• $(-1 ~|~ 0)$

• $(0 ~|~ -1)$

are on the unit circle.