Finding values of cos(x) and sin(x) with the unit circle - Fourth Quadrant - Tutorial 4

In this tutorial we learn how to use the unit circle to find values of sin(x) and cos(x) for angles in the 4th quadrant of the xy grid i.e. angles between 270° and 360°.
The method is clearly explained using the coordinates of a point moving along the circumference of a unit circle.