Calculus IV
15.Functions of Several Variables
16.Multiple Integration
17.Vector Analysis
Course: Trigonometry
Topic: The Six Trigonometric Functions
Subtopic: Basic Identities


Now that we have defined the six trig functions, we can begin to find relationships between them. These relationships are called identities. We will use these identities to simplify trigonometric expressions and to create even more identities. Simplifying a trig expression can be accomplished in many ways but the goal is to get it as simplified as possible.

The major techniques used to simplify a trig expression are:


By the end of this topic you should know and be prepared to be tested on:


Memorize the 3 reciprocal identities, the 2 ratio identities, and the 3 Pythagorean identities. These are too important and used too often to just have on paper. Commit them to your memory!

Supplemental Resources (optional)

Videos from James Sousa's MathIsPower4U:
Mini-Lesson: Trig Identities:  Reciprocal, Quotient, Pythagorean
Mini-Lesson: Fundamental Identities:  Reciprocal, Quotient, Pythagorean