Definitions (Trigonometric Functions (Secant: The Reciprocal of a Cosine.,…
, The Unit Circle
, Radians and Degrees: Radians are the units of angles. Degrees are units of measurement of angles
, How to convert from one set of units to another:
-Write the conversion as a fraction
-Cancel any units that are both top and bottom
, Terminal, co-terminal, and reference angles: Terminal side is a straight line that has been rotated around a point on another line to form an angle measured in a clockwise or counterclockwise direction. Co-terminal angles are angles who share the same initial side and terminal sides. Reference angles are the smallest angles between the terminal side and the x-axis.
, The line where it says 30 degrees is the co-terminal angle. The reference angle is 30 degrees. The terminal side is 390 degrees.https://i.imgsafe.org/0ab61d16bf.png
, Positive and Negative angles: Negative angles are a way of measuring an angle from a different direction. A positive angle is created by rotating counter-clockwise around the origin of a coordinate system, starting at the x-axis (the horizontal axis) and proceeding through the quadrants in the order I, II, III, IV.
, Examples of radians and degrees:
, Example of positive and negative angles: