Degree:

A degree is a unit of angle measurement equal to 1/360 of a circle’s circumference.

 Radian:

A radian is a unit of angle measurement that is the ratio of the circle arc cut off by an angle to the central angle.

 Sine:

Sine on a unit circle is the “y” coordinate for any intersection between a standard angle and the circle.

 Cosine:
Cosine on a unit circle is the “x” coordinate for any intersection between a standard angle and the circle.

Tangent:

The ratio of sine to cosine or, in a right triangle, is the ratio of the length of the opposite side to the length of the adjacent side.

Reference Angle:
A reference angle is the angle between 0 and 90 made with the x axis.

Form of a Trigonometric Function:

 Trigonometric functions take the form where A,B, C, and D are coefficients that change the characteristics of that trigonometric function.

Graphs of Trigonometric Functions:

Graphs may be affected wildly as follows:
Stretching or compressing it along the x-axis
Stretching or compressing it along the y-axis
Moving it up or down along the y-axis

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Core Concept Tutorial	Problem Solving Drill	Review Cheat Sheet

Trigonometry is an important branch of mathematics that uses angles and the definitions of the basic trigonometric functions to solve equations. Angles are given in degrees and conversion to radians is performed using the fact that 180 degrees equals to pi.

The basic trigonometric functions and their graphs are shown with the use of examples and and graphical representations. Trigonometric identities are presented and how are they use with reference angles. The sine and cosine functions are defined on a unit circle and a triangle.

Specific Tutorial Features:

• The properties of the trigonometric functions are shown in some of the examples.
• Measuring angles is presented in the examples.
• Step by step explanation of how degrees can be converted to radians and vice versa.

Series Features:

• Concept map showing inter-connections of new concepts in this tutorial and those previously introduced.
• Definition slides introduce terms as they are needed.
• Visual representation of concepts
• Animated examples—worked out step by step
• A concise summary is given at the conclusion of the tutorial.

Measuring Angles
            Definition of angles and radians
            Comparison of degrees and radians 
            Definition of sine and cosine functions
            Definition of a tangent function
            Definition of reciprocal trigonometric functions
            Trigonometric Identities
Graphs of Basic Trigonometric Functions
            Definition of the form of a trigonometric function