• #### Using the Sine and Cosine Addition Formulas to Prove Identities - Problem 1

How to use the sine and cosine addition formulas to prove the "add pi" identities.
• #### The Half-Angle Identities - Problem 1

How to use a half-angle formula to evaluate sin(/8).
• #### The Half-Angle Identities - Problem 2

How to use a half-angle formula to evaluate cos(105).
• #### The Half-Angle Identities - Concept

How to use the power reduction formulas to derive the half-angle formulas.
• #### The Half-Angle Identities - Concept

How to use the power reduction formulas to derive the half-angle formulas.
• #### The Half-Angle Identities - Problem 1

How to use a half-angle formula to evaluate sin(/8).
• #### The Half-Angle Identities - Problem 2

How to use a half-angle formula to evaluate cos(105).
• #### Trigonometric Identities - Problem 3

##### Math›Trigonometry›Trigonometric Functions
How to use the unit circle to show that sine and cosine have period 2*pi, and tangent has period pi.
• #### The Half-Angle Identities - Problem 3

How to use the double-angle formulas for sine and cosine to derive a half-angle formula for tangent.
• #### Trigonometric Identities - Problem 3

##### Math›Precalculus›Trigonometric Functions
How to use the unit circle to show that sine and cosine have period 2*pi, and tangent has period pi.
• #### The Half-Angle Identities - Problem 3

How to use the double-angle formulas for sine and cosine to derive a half-angle formula for tangent.
• #### Using the Sine and Cosine Addition Formulas to Prove Identities - Problem 3

How to use the sine and cosine addition formulas to prove a difference formula for tangent.
• #### Using the Sine and Cosine Addition Formulas to Prove Identities - Problem 3

How to use the sine and cosine addition formulas to prove a difference formula for tangent.
• #### The Reciprocal Trigonometric Functions - Concept

##### Math›Precalculus›Trigonometric Functions
How to define the reciprocal trigonometric functions, the reciprocal identities, and the Pythagorean identities.
• #### The Reciprocal Trigonometric Functions - Concept

##### Math›Trigonometry›Trigonometric Functions
How to define the reciprocal trigonometric functions, the reciprocal identities, and the Pythagorean identities.
• #### Graphing the Reciprocal Trigonometric Functions - Concept

##### Math›Precalculus›Trigonometric Functions
How to use the unit circle to derive identities that are useful in graphing the reciprocal trigonometric functions.
• #### Graphing the Reciprocal Trigonometric Functions - Concept

##### Math›Trigonometry›Trigonometric Functions
How to use the unit circle to derive identities that are useful in graphing the reciprocal trigonometric functions.