These lessons, with video lessons, examples and step-by-step solutions, help Algebra 2 students to
learn about the trigonometric function: Sin, Cos, Tan and the reciprocal trigonometric functions
Csc, Sec and Cot. Half-Angle formulas, Product and Sum Formulas.

**Related Pages**

Trigonometric Functions

Trigonometric Graphs

Trigonometric Identities

Lessons On Trigonometry

The following diagram shows the trig identities: Reciprocal Identities, Pythagorean Identities, Half-Angle Formulas, Sum and Product Formulas. Scroll down the page for more examples and solutions on the trig identities.

**Reciprocal Trigonometric Functions**

There are three reciprocal trigonometric functions, making a total of six including cosine, sine, and tangent.

The reciprocal cosine function is secant: secθ = 1/cosθ.

The reciprocal sine function is cosecant, cscθ = 1/sinθ.

The reciprocal tangent function is cotangent, expressed two ways: cotθ = 1/tanθ or cotθ = cosθ/sinθ.

**How to define the reciprocal trigonometric functions, the reciprocal identities, and the Pythagorean identities using the unit circle?**

**Fundamental Trigonometric Identities: Reciprocal, Quotient, and Pythagorean Identities**

Use reciprocal, quotient, and Pythagorean identities to determine trigonometric function values.

**Trigonometry Functions - Sin, Cos, Tan, Csc, Sec and Cot**

**Tangent, cotangent, secant, and cosecant of any angle**

**This tutorial covers the reciprocal identities and shows them in various forms.**

**Product To Sum Identities and Sum To Product Formulas**

This trigonometry tutorial explains how to simplify trigonometric expressions using the product to sum identities and how to find the exact value of trigonometric expressions using the sum to product formulas.

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