[Index]

	Introduction
	Essence
	Memorizing How to memorize Basic Formulas Sum and Difference Formulas Double & Triple Angle Formulas Half Angle Formulas Product to Sum Formulas Sum to Product Formulas All Formulas
	Understanding Page 1 Page 2 Page 3 Page 4 Page 5
	Summarizing Page 1 Page 2
	Examples Examples Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 General ideas
	Exercises
	Final thoughts

Basic trigonometric identities

These formulas are very important.  You shouldn't go any farther without knowing them. If you already know them, you can go ahead and continue to the next page.

Quotient Identities
Reciprocal Identities
Pythagorean Identities
Even-Odd Identities
Derived formulas

Reciprocal Identities

Pythagorean Identities

Even-Odd Identities

Derived formulas

, if k is an odd integer,

, if k is an even integer.