Special Angles &
Circular Functions
Plane Trigonometry
Recap: How to Plot on the
Cartesian Plane
Plot the following
points:
1. A (2, 3)
2. C (-4, 6)
3. P (5, -3)
4. X (-6, -6)
The Unit Circle: Cosine
and Sine
Unit Circle - a circle having a
radius of 1
The x-coordinate of point P is called the cosine of θ while the
y-coordinate of P is called sine of θ.
Principles to Remember:
Pythagorean Theorem
Equilateral Triangle
Sum of the Angles
of a Triangle = 180°
The Pythagorean Identity:
Example:
Non-Quadrantal Angles in
Other Quadrants:
Example:
Where: π / 6 is called the Reference Angle, usually taken as α
Reference Angles:
Reference Angles:
Reference Angle Theorem:
Example:
Example:
Assignment:
Note: solve in radian measurement.