What is the unit circle in radians?
In this post, we understand the unit circle definition of sin, cos and tan and periodicity using radians, as a part of the Prelim Maths Advanced course under the topic Trigonometric Functions and sub-part Radians.
The following two videos goes over the unit circle definition of trig functions and how it is used and represented on a unit circle.
Part 1
Part 2
Examples involving the unit circle in radians and degrees
This video goes over a large number of questions on unit circle trigonometry calculations to find values.